Tweeted by David McAffee, AMD's CVP and GM of Ryzen channel business, the $125 price is a promise that AMD made back when it launched the Ryzen 7000 series and AM5 socket motherboard. He also points out that his timing was a bit off, but at least it is now hitting the promised price, and not even with an entry-level A620 chipset that is coming a bit later.

When AM5 launched I said that we would see motherboards starting at $125. As @HotHardware noticed, my timing *might* have been a bit off... (https://t.co/TJtRCUirxY) but I'm happy to see that ASRock is first to market with a $125 B650 board for @AMDRyzen https://t.co/c19zLBnTNs pic.twitter.com/G6CKqfx57I

— David McAfee (@McAfeeDavid_AMD) March 9, 2023

The ASRock B650M-HDV/M2 is a microATX motherboard with support for Ryzen 7000 series CPUs, up to 64GB of DDR5-6400+ memory in two DIMM slots, and has an 8+2+1 Dr.MOS VRM. Since it is based on a standard B650 chipset, it is limited to PCIe 4.0 x16 slot for graphics, but has single PCIe Gen5x4 M.2 slot.

The rest of the specifications include 2.5Gb Ethernet, 7.1-channel audio, a couple of USB 3.2 and USB 2.0 ports, a few other M.2 slots, and four SATA 6Gbps ports.

Considering that the least expensive AMD AM5 motherboard were, and still are, selling at around $150, the $125 price for ASRock B650M-HDV/M.2 sounds like a pretty good deal.