I bought an a3000 motherboard off ebay for 100 bucks. I did a little hack jobbie to get it powered off a spare atx powersupply i got from a case i found in a trash can... I bought a kb for it off ebay for next to nothing.
If you dont have the resources to buy a cheap amiga, why not just use UAE? It's free and gives you way more flexability anyway. I bought an a1000 to play old games again, but i ended up using UAE instead. No more screwing around with stacks of floppies or waiting for crap to load. UAE means i can take that pimp 21" lcd i just got and drive it at 320x200x32 colors and draw stick figures in dpaint.
At the very least, you could have offered to detial somebodys car or service their wife for a box.