I never use caps to buy anything, I always trade various assorted junk for what I need so my characters are always minted. My current character is level 26 or so, has a fully kitted out house and has invested the maximum amount of cash in all four trade caravans, and still has around 12,000 caps.
Also I generally only use Small Guns as my offensive capability, so after every mission/exploring trip I come back with shedloads of 5mm rounds, flamer fuel, energy cells etc that I can just flog off if I need money for anything. Ammo is weightless, as are drugs, so ECP packs and Jet are a much better way of accumulating wealth than picking up sensor packs and conductors.
Also I generally only use Small Guns as my offensive capability, so after every mission/exploring trip I come back with shedloads of 5mm rounds, flamer fuel, energy cells etc that I can just flog off if I need money for anything. Ammo is weightless, as are drugs, so ECP packs and Jet are a much better way of accumulating wealth than picking up sensor packs and conductors.