I reccomend you to play those 4 days and see how the game will dramatically change after Wargots arrive. Trust me - you`ll salvage lots of pechenegs, rg6s, m202s, scars, p90s, umps, barrets (both for cyborgs and normal men), b2m mgs and tons of various cultist-wargot stuff, cyborg stuff and advanced/energy guns. Just make sure you play as many various missions as you can (especially 'help local troops' ones).
Also you should know that the game is divided into several phases. Each phase has its own equipment sets for all factions.
The first one is exploration where you meet the new guys and fight mutants and rets.
The second one is quite long. It starts as soon as you meet Cultists. It lasts until the first Wargot mission.
After that there are 5 more phases, so you must understand that the equipment is progressive and you are just playing the 2/7 of the game right now. Really you should not be able to build everything so fast. You`ll get acess to all available scopes and atachements (except for those unique ones used by cultists). You`ll be able to develop powerful laser and plasma weapons as well as a set of advanced grenades and mines. You`ll be able to produce cyborg-only and drone-only weavy weapons.
Quitting so soon is a bad idea