ASUS’s Mining Expert MB is a good board, best of it’s time, and their Mining Master is probably the best mining motherboard available to this day. I started out with B250s w/ i7 7500T and have since replaced most rigs with their H370s with i9 9900T. I say most, because I can’t find anymore available on the market to upgrade the remaining rigs with. 1.5 years since the H370 launuched and no newer mining MB released since, guess future tech is on hold until alt season is in full bloom.
You should consider using eBay or Reddit HardwareSwap or bitcointalk.org market for good deals on hardware. I buy most of my cards used on eBay. 27% of my GPUs are Turing, and yet I only bought 1 or 2 new at retail, the rest I purchased 2nd hand new or used off eBay (lowest price on net, no tax, free shipping, 10% eBay bucks, 1.5% back from Chase Freedom).