Nope. A game box fits your description of desires.
Any computer you put together to run that game will be overkill for just about anything else except true rendering.
Meh... I know the main-stream is behind (as ususal). Now all these youtube schmuks have learned a new vocabulary word. Most of this mining is over but the crying. It's become so devalued that the power bill necessary to pull this off makes it counter-productive.
Video card prices as I have observed them have always been pretty high and have remained relatively high. The other part of this depends on what level of performance you want. It doesn't require much of a video card to equal the performance of an X-box or even a PS4.
A desk top computer is not handicapped by a 300 watt power supply.
Here's a relatively cheap video card that will outperform either of those boxes with and I3, I5, or I7 system with 8G:
https://www.newegg.com/Product/Prod...50&cm_re=gt_740_sc-_-9SIADRA6PV1050-_-Product
This solution of course, doesn't satisfy your other requirements so the game box is still your best option IMO.