I think if you look at your local used listings and ebay you should be able to get something that fits the bill. If cost up-front is a concern, then operating cost is also a concern, so you should be considering power draw of the system as well.
I used this spreadsheet to help me choose a recent Lenovo M710 SFF (i5-7500) build I did for pfsense. It’s not perfect, not all mobo pairings are included, but it gives a starting point for power consumption.
I think if you look at your local used listings and ebay you should be able to get something that fits the bill. If cost up-front is a concern, then operating cost is also a concern, so you should be considering power draw of the system as well.
I used this spreadsheet to help me choose a recent Lenovo M710 SFF (i5-7500) build I did for pfsense. It’s not perfect, not all mobo pairings are included, but it gives a starting point for power consumption.