There's no money left in the regular budget for projects once our bills are paid. I do a lot of horse trading for stuff. I also check craigslist and the local trading post frequently and ****** up killer deals if I find them and think I can turn a few dollars on it. Takes time - but at least I eventually get what I need. I recently bought three complete 351W long blocks and a pile of spare starters, alternators, manifolds, etc. for $125 from a company retiring a fleet of work trucks. Their new trucks used the 5.4 mod motors and they had no use for these old cores. I sold two of the motors for $75 a piece and now have a core for my next rebuild - more **** to sell, and a few dollars left in my pocket to put towards parts. I keep a small bit of cash on hand to pick stuff up fast when I find it. Not the fastest means to an end, but I enjoy the scavenging and I can buy parts without feeling guilty about pillaging the family budget. They go fast, but you wouldn't believe the **** people give away on craigslist - I've gotten a free 352FE complete motor and free 351M long block - both need to be rebuilt, but free is free! I have a small crane bolted into the back of my pickup so I can lift a motor, trans, rear, whatever into the bed of the truck quickly and easily without help. A lot of times people just want **** gone and if you're the first one there with means of moving it, SCORE!
Mrs. Cajon and I have this same arrangement. It takes a fixed amount to run the household each month and we both contribute half of that automatically every month. The rest is our own business. I can't imagine what it would be like to ask permission to spend the kind of money this hobby can require at times.