That is a pretty good price estimate. Some of the first ones we paid a lot more than we should have and more recent ones we got for less.

We are currently paying $20k USD for Avalon 3 module units or 5k per module if you just have the modules (ie: defective unit etc).
Though we are lowering this price by around $200+ a day as value gets extracted from them at that rate (based on the calculations below).

71000 MH/s, earns 2.28807817 BTC/day ($232.24) on average (0.09533659 BTC/hr) with the current difficulty of 15605632.68129 but in 7 days somewhere between 15% to 25% raise in difficulty.. right now its projected at 18.55% but who knows.. it might pull another one like last week but I doubt it.. my bet is 20%.