We won't have to, but the prices I posted yesterday were from an Italian retailer, to demonstrate that the prices shown by some click bait website were just that, click bait.
Distributors will have loads of stock, and as I mentioned the allocation of parts seems to be un-problematic presently. I am pretty confident that every major UK retailer including OCUk will have stock, and based on that will price them appropriately, due to the value add form securing a motherboard, RAM and possibly cooler sale at the same time, or in some cases entire systems.
I don't think you'll have any issue buying an older generation board, and putting a 3700X - 3900X on them, much to the annoyance of some people who seem to be trying to convince people otherwise. I think the main factor for older boards is ensuring that they are given regular BIOS updates if changes are made along the way.