gin is a lil high because on the xbox 400 points are 5 dollars and on here 1,500 is 5 dollars so 7,500 is way to much but 3,000 wouldn't be to bad but f&w
1500 is the SET about for 5 dollars through listia. For example, check out how much $1-$20 gift cards go for on here. They always sell for 1000+ per dollar. 100 Microsoft points usually go for 1500 and a lot of times go for 2000+. Also, credits are free in a sense to a lot of people that are willing to do a few free offers and surveys. 7500 IS low for a gin on this and many people tend to buy them up left and right at this amount.
You must become verified to be able to bid. Go to: http://www.listia.com/support/topic/verify?from=1 and look at the verification level 1. That is what you need and fastest way to get bidding! Hope that helps!