I've only just finished my first year of ambulance-chaser school, but I did learn a little about contracts. Aaron talked to the seller. They bargained for a deal - the seller offered Aaron the bike, shipped, for some amount and he agreed and said he would put his check in the mail. When his check WAS actually in the mail he formed a CONTRACT to buy the bike. Someone else came along and offered the seller some more money, cash, right now, and he took it. The seller BREACHED the contract he had with Aaron. If he took more money for it than he had agreed to take from Aaron, he OWES Aaron at least the ill-gotten difference.
Businesses pull this shit all the time on each other and they get sued for it for a lot of bucks.
I've sold things on Craig's List and it pays to know how you're going to deal with the many people who will pop up and want it. Are you going to sell it to the first person who shows up with cash? Will you take a Paypal payment as a deposit so they have an option? Checks? How do you deal with the order of callers, none of whom can come right now?
David Bean
Arlington, MA
beandk at are-see-enn dot com