I have been waiting to find one at a reasonable price, and Stillwater Armory posted up 4 on their facebook page today for $224, which is normal retail. These days, that's a bargain!
I got a Tactical industries Targetmaster brand new this week for $180 to my door off Gunbroker.
Took it out yesterday and works like a champ.
If you look at Blackdog Machine's website you will see they sell them too, but are out of stock.
Blackdog does have x-form mags in stock for $20 each.
FYI, Cabela's has the CMMG conversions in stock for $209.99. I don't know what the difference in shipping between the two is, so the Stillwater Armory deal might still be better.