Much was lost in the Calamity, but survival was sure enough to prevent losing much. The means to make a great many things have been forgotten or rendered unavailable, but that it can be done and a vague notion of how to do it has not. Retained knowledge and production capacity generally sits at TL6, but prices listed in High Tech assume factories, assembly lines, and other modern production systems. However, in a world where most people have nothing but time, labor is cheap. Any equipment that is TL6 costs 1.5X list price to represent difficulty in obtaining materials, lack of production streamlining, and other such niceties normally available to TL6 societies. TL7 equipment similarly has the same penalty due to lack of mechanized and modernized production and such, and is harder to manufacture. Building a TL6 version has the usual 2x price and weight penalty if the main differences between it and lower tech equipment are simply design refinement and higher quality material components or manufacturing techniques. New equipment requiring specialized equipment or rare resources costs 5x or more, with potentially massive penalties, if it's available at all for new production. Surviving TL7 gear from before the Calamity almost always has the Rugged enhancement, for 2x cost and 1.2x weight.
Equipment from before the calamity is highly prized, with a particular interest in medical gear, things that can be reverse engineered, and old world media for entertainment. A number of items have been developed that would normally be treated as higher TL gear, but developed early out of necessity.
Batteries are a significant problem in the Metro, but are required for a large amount of useful lifesaving equipment. Disposable dry cells are rarely used, but new production of reasonable quality rechargeable batteries has been mostly perfected. Due to problems with materials, the total cost of batteries is 10x list price; because they can be reclaimed and remanufactured, a completely worn out battery retains a substantial portion of its value as scrap.
Armor in the metros tends to be rough around the edges. High end synthetic fiber armors tend to degrade with age, and the chemistry to manufacture new ones isn't presently available. However, most guns tend to be lower power, and high tech versions of old fashioned armors are available. Leather, both from metro-bred livestock and various surviving creatures, tends to be common and reliable, used either as a base to which other armor is sewn, or simply as a covering with just a bit of additional durability. Armor incorporating steel uses High Tech Low Tech rules, offering either 1/2 weight and cost at no loss of DR, or 2x DR at no weight or cost penalty. Because quality steel is so widely prevalent even as salvaged scrap, the only difficulty is space and fuel to work it, for a mere 1.1x price. Armor listed in High Tech already incorporates these rules, apply only to gear purchased from Low Tech or Basic Set low tech armor.
Shields are of moderate commonality. Thanks to the improved toughness of high TL steels, steel shields have a good chance of absorbing the entirety of the common pistol rounds used by most Metro inhabitants. Damage to Shields rules are in effect; shield will eventually at least need the dents pounded out and a bit of re-tempering, even if it is not penetrated by damage.
Compact Battery Charger (TL6+1), $100, 4LB
Combination gadget, incorporating a refined Portable Muscle Powered Generator (High Tech 14) and a Survival Flashlight (High Tech 52). Using a squeeze, crank, pull cord, or other mechanism, it can charge a battery or provide external power. Sometimes combined with a bank of Small batteries or a Medium battery, and wired to worn equipment to provide power, rather than carrying a number of individual batteries for each device. Operating the generator can power the dynamo to the survival flashlight, or provide a slight boost in power supplied to connected devices being powered by the battery.
Miniature Radiation Warning Device (TL6+1), $150, .2LB
Using a miniature Geiger-Mueller tube without any additional circuitry beyond what is absolutely required, this device provides an audible or visual alert in the presence of moderate quantities of radiation. Lacking any gauges, it counts as improvised equipment for science rolls relating to radiation requiring more detail than determining whether something is emitting some manner of measured radiation. The device is about the size of a pack of cards or a pager, and typically is purchased/built with the Rugged enhancement. Alone it is clipped to a belt or other equipment. It often includes a slot for a single use Radiation Badge (High Tech 49). Uses batteries, 2xXS/2 months
Radiation Warning Wrist Kit (TL6+1), $225, .3LB
A combination version of the above device incorporating and possibly concealing a number of other small gadgets of negligible weight (pick 2), such as a watch, compass, detachable multi-function knife, cigarette lighter, wire saw, magnifying glass, pocket torch, very tiny light, etc. Almost always ruggedized if possible (always applied to the radiation warning device, optional on combined gadgets).
Breath-EZ Matches (TL 6+1), $.25, neg weight, per 50
Regular waterproof strike anywhere matches with an extra bit of alchemy in their creation. A simple "detect poison" spell worked into the mix, they burn and smoke purple in the presence of poisons, toxins, and anything else airborne that's hazardous to a humanoid system. They're still a light and ignition source, though.
Chemstrips $75, .5 lb
Paper strips treated with various chemicals to react in the presence of different chemicals, sold as a stack similar to sticky notes. A kit will have 25 strips of each kind for the various chemicals they react to. When it reacts, the paper will turn black. Tear the strip that reacted off when you think you're clear of the hazard zone to check if it's safe to breathe. Improvised equipment for scientific purposes when determining what's actually in the air or water. Reaction is instant on exposure to chemicals.
Chempatch $150, .5 lb
A bit of alchemy and the principle behind chemstrips gets you the chempatch, a small badge that reacts in the presence of ANY harmful airborne contaminants. It goes from green to yellow to red to black. What makes it special is that it turns back. It will wear out after about a year of exposure to hazardous conditions, but most people will never accumulate that much time (either by virtue of avoiding it, or failing to survive).
Chem Detector $300, 1 lb
Combines a chempatch with a bit of simple electronics to produce light or sound on exposure, giving a distracted traveler a better chance of noticing the hazard. Can be set to Light, Sound, Both, or Visual Only. Sticking a radiation warning device in it adds negligible weight, and costs an extra $100. 2xS/2 months.