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I had a vehicle priced for 4500$ on craigslist.  I had overpriced it a bit and was only expecting to get around 3500 for it.  A guy made an offer of 3000 dollars which I would do if I could secure a loan for a new vehicle I want.  The guy put 100$ down on the vehicle, and I wrote a note and signed it which state the following.

"100.00 down on sale of 3000.00.  Sale contingent on securing vehicle prior to transfer."

For the past few days I have been trying to secure a quality loan with no luck.  In the mean time I received an offer of 4000.00 for the vehicle.  Would it be illegal to give the guy his 100.00 back and accept the other guys' offer?  I will not be purchasing the new vehicle at this time due to financing.

Please let me know.  I don't want to make a wrong move.