for those that still want to change region to buy cheap games, i have tried and am still using this method, but as usual, YMMV
you need 2 different PC to "bypass" steam detection that you are changing region for cheap games.
first on your main gaming PC, make sure you are logged into steam, both in browser and in game app, then DO NOT LOG OUT.
use the 2nd pc to login again with VPN to change your region from the web browser, i changed mine to turkey.
your main pc will now auto update to reflect the new region store.
now to easily bypass the pesky requirement payment with a region credit card, just go to the online store of your choice and buy steam gift cards and load your account that way.
for my turkey region switch, i use
https://www.trendyol.com/sr?q=steam&qt=steam&st=steam&os=1 and they have 10% off the steam gift cards every so often, making the games even cheaper.
i just leave my account now in the turkey region.