Or do like I did. I bought an older Mercedes for $200 at a garage sale, stating that the parts alone were worth more than that, and there was a possibility of getting it running. Found out the head was cracked on it, so let it sit for five months, then sold it for $400 (still a heck of a deal considering the parts left on it). Made $200 and there is NOTHING she can complain about regarding it. She asked once how much I spent trying to get it running, and I told her "$13 for a new ratchet and some feeler guages." End of story.
Now when I look at something to "buy cheap and sell for more later on", the only thing she can complain about is the fact that it might sit for a while. ::