Over the years, I've been pleased with the vast majority of the koi I have gotten from the Kodama auction, which has a wide range of quality, size, and price. You might have to check the auction several times over a few weeks to find a nice one that will go for under $200, as most will cost more than that. While it is still cool whether and not so many are bidding, you may have a better chance of snagging a bargain.
I have had my best experiences with PSKoi and Genki.
I'm near San Antonio, Texas
Pskoi and USA koi for me.