Bought a 5600x through one of the deals recently posted and realised I now need a new motherboard too. You can save yourself a few bucks by buying the older B450. Also it seems AMD might be releasing a new socket soon anyway
Saw this on Amazon, and this is pretty much the cheapest price it's ever been.
NOTE: I'm pretty sure you need to flash the bios for the B450s to be compatible (i.e. you will need an older AM4 chipset or will need to ask a store/friend to do for you)
Alternatively, if you need your BIOS flashed, could try purchasing direct from landmark who have it for $129 + shipping and email them to see if they'll flash for you.
Otherwise you'll need to buy a B550 or X570 for compatibility out of the box
EDIT: landmark computers was cheaper for me. $129 with free shipping in Melbourne
I have this motherboard. Good motherboard but terrible VRM. Hit's 95 - 100 degrees with a 5900x.