It’s hard to know what you consider “cheap” but you can buy a 1-3 year old iPad for relatively cheap (iPad 9 renewed on Amazon goes for about $240, WIFI-only). If you are just running a HA dashboard then an iPad is going to be rock solid.

I know that is going to sound counter to what you think you want but it will be plug and play and you can be sure it’s not going to have crapware loaded on it.