I'd remecomend a system that is something along the lines of:
AMD Ryzen 2200G
B450 Motherboard
8GB RAM
A cheap case with decent airflow
A decent good power supply like a Corsair CX450 or EVGA 500B
How ever much storage you need, preferably with SSDs.
That should probably cost you no more that $400.
It would have decent CPU power and not horrible graphics power.
It would also be on an upradeable platform that would alow for upgrades if they are needed.
Hope this helps, Let me know when you have a final parts list or if you need more help.