Thanks a million for clearing that up for me!

Thanks for your reply! That's exactly what I was hoping.

I assume, however, that there is some way for the seller to cancel the transaction if they think to themselves "I didn't expect the price to drop this low, I don't want to sell any BTC at this price"? I'm thinking specifically of a situation where the market crashes, for example.

Quick question regarding LocalBitCoins.com which relates to the thread.

If someone is selling a BTC for $1000, at what point in the buying process am I locked in at the $1000 dollar price?

For example, if I click buy for $1000 and send the money, can the seller wait a few hours for the value of BTC to rise and then only send me the 0.9 BTC that my $1000 is now worth? Or if my bank transfer takes 3 days to arrive am I exposed to whatever price changes happen in the market?