~450 eur in total, I bought all of them used.
But most of the price came from maxed out ram and quad core cpus.
For something cheaper, I can find in my country lenovo tiny m72, for something like 40 eur. No SSD/Ram, you can configure it as you wish (and still will be cheaper then RPi, even after adding like 2GB of ddr3 - it's something like 4EUR per stick, there are 2 slots in each machine).
That is with Intel Core i3-2120T, so would expect much more performance then even RPi4
Edit: I see now that the same seller has them for ~72eur with 120GB of ssd and 4GB of ram if someone wants something ready to use.
For something cheaper, I can find in my country lenovo tiny m72, for something like 40 eur. No SSD/Ram, you can configure it as you wish (and still will be cheaper then RPi, even after adding like 2GB of ddr3 - it's something like 4EUR per stick, there are 2 slots in each machine).
That is with Intel Core i3-2120T, so would expect much more performance then even RPi4
Edit: I see now that the same seller has them for ~72eur with 120GB of ssd and 4GB of ram if someone wants something ready to use.