Nice domain, 3 letters are hard to come by. But 15 Bitcoins, that is quite a lot!
The valuation is usually around $17,000 to $100,000 depending on it.
0.3 to 1.7 BTC.
It's unethical to comment on auctions, especially when you're not very informed about the product on sale. UTD.com is a high end LLL domain with multiple use cases. Such name is Valued in millions of USD in aftermarket.