I Have a Zebra finch in my First enclosure, Called Marionette and I'm selling it ! But I'm not sure how much to sell it for ? So please take a look and Reply how much please ;")) And I'm not sure how to put pictures up on Forums ?
I looked it up, and since it's a starter you can definitely get more than 10k. As we speak (or type, lol) there are only 13 male adult peg finches on the market. The prices range from 10k to 16 million with most in the 50k range. So, if you don't mind holding on to it for a while go with 50k, if you want it to sell quick go for 20k.
And, don't feel bad making money off resales. You paid the original seller what they wanted, and your stable space is a resource just like pg and bp are. I do it all the time, and if people think that's cheating they can go read the rules. It's probably the quickest way to make pg. Especially when you're starting out.
10k I'd say, since that's how much you bought him for
How much a person buys a pony for is generally irrelevant just because the pony market fluctuates and there are so many other forms of payment to combine with PG.