You should get more than 15,000 for this hun. Right now 20,000 credits is equivalent to $1.00 There's always people who try to low ball and I block every one of them.
I know it does kind of suck when you're first starting out but after you get your trusted seller badge you'll be able to increase your starting bids. I will be bidding on all but 1 of your auctions. Don't get discouraged. Most people wait until closer to the end to start putting in higher bids and also, once you're a trusted seller buyers do tend to bid more. ( I already have 75,000 on your A6 cards and will bid a lot more! We just need people to start competing) I remember how it was being new and at one point I really thought of giving up on this site. I'm so glad I didn't do that. Now I absolutely LOVE listia. Good luck to you and if you have any questions please feel free to message me. I was lucky to have a few ladies who helped me out in the beginning and I would be happy to pay it forward.