Nigh on impossible to find any mini itx board for less than £100. It stupifies me that amd wont have the B550 chipsets ready until next year. Lots of people will buy into it brand new and have get the supplier to do bios updates for the 3 and 400 series boards.
I've actually already fully built my AMD ITX, in anticipation of Ryzen 3000. The mobo was $139 (dollars is different, I know) but I saw it drop to $109 and bought. B450 board. I literally finished the build last night. I had to buy a cheap AM4 cpu to update the BIOS since my board doesn't have Q-flash or similiar. I won't be waiting around for the new chipset. I have a custom air cooler which should sufficiently cool a 12-core or lower. All I have to do is wait for Ryzen 3000 to launch...wait for some benchmarks... and buy my cpu and drop it in. Once configured, I expect my little ITX to run plenty cool. (It's actually a large case for ITX). I even replaced the thermal paste on the new gpu. While everyone is on pause, I got my hardware during the last few weeks while there is availability and decent prices. I have waited for over a year--having never pulled the trigger due to lack of real options. So the trigger is pulled. It's a pleasant little powerhouse waiting for a 3700X (probably). Once everyone figures out that X570 is overkill for the lower-end processors, you can expect X470/B450 mobos to go extinct. It won't be an issue for me, as I take my own advice.
Although Saggar's, Bottom Knocker's and dialects of Christmas poems have not much to do with AMD cpu's....it's one of the better side tracks I've seen in these forms!