I can not answer that, because I am not located in a place that use dollars. 
You probably have to start a new thread about that question and remember to state your location then.
This thread is marked as solved and with another topic, so many might skip the thread.
Neither do I, use euro for me would be under 200 euro 
It was just to make the point, a device that costs about half as much as a Nuc
Raspberry I have seen that doesn’t cost cheap
Refurbished computers are sometimes used.
They are often cheap and powerful.
Laptops can also be a good platform, as long as you remember to check if there a setting to start the computer after a power failure. Some have it, but not all.
A side benefit with laptops is that the battery works as a UPS for the machine and it is often easy to get the power data into HA to make automation on.
I installed proxmox, it was very easy with the guide.
Now I’m trying to get the Wi-Fi card working without success… with chatgpt I’ve tried various commands and installing various components but nothing… the card is available but remains in the ‘Down’ state
wlp0s20f3: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
link/ether 50:76:af:c0:62:3c brd ff:ff:ff:ff:ff:ff
do you know a guide also for configuring wifi, which is activated when the lan network fails, and how to configure bluetooth as well?