"Acceptable" compared to what? In the UK this board is £180-£200. In comparison the B460M Mortar Wi-Fi (same onboard Wi-Fi 6, Bluetooth 5, same layout + VRM heatsinks, etc) is £90-£100 whilst B550M Mortar Wi-Fi (same features but PCIe 4.0) is £145 so the PCIe 4.0 premium is more like +£45 than +£100. In fact many Z690 boards (including Phantom Gaming & Aorus Elite DDR4) are cheaper than this B660 one, whilst this B660M board costs £70 more than an ASRock H670M and +£100 more than most H610M, and Bxx0 boards are supposed to typically sit between those two tiers, none of which make any pricing sense at all. I feel that some enthusiasts (inc tech site reviewers) are so wrapped up in number chasing they've lost all context that what determines "budget" is actual price, and there's really nothing here that justifies a doubling in price at all for the same low-end target market that cares about NVMe SSD CrystalDiskMark p*ssing contests the least.
The "Mortar's" are great boards in general, but compared to exactly the same Mortar Wi-Fi B460M / B550M boards, someone's really price gouging these, and all it's convinced me is that if I were on a budget then go buy either a (B550M + Ryzen) or (B460M + 10th Gen), but if you want 12th Gen premium-ness then simply ignore the price-inflated B660 boards and just get a Z690 one for barely any extra money...