maksi, a raffle is like a lottery. people spend a certain amount of money like $1.00 for one ticket. they buy as many tickets as they like. after all the tickets are sold, a number is chosen by the owner of the quilt. the owner doesn't know who bought that number ticket. the person who has the ticket with the matching number wins the quilt.
you do this when you think you can sell a lot of raffle tickets. if your item is valued at $500.00, and you're selling $5.00 raffle tickets, then you have to believe that you can sell 100 of them to make the right amount of money. if you sell less, then you make less. if you sell more, then you make more.
if you auction it off, you might only get a low bid, unless you establish a bottom price which means that only prices above that one are acceptable.