Are we talking 2 or 4 or 20 drives? Most OEM desktops only support 2-4 drives of any type. If these are to be used for important storage, this is the wrong approach.
If you want backups, it should be some network attached storage with its own tape backups, or a cloud storage provider as backup.
As scratch drives for getting stuff done before copying to permanent storage, okay.
Not really seeing anything in that price range that isn't extremely old.
Look at Dell Precision workstations and HP Z class workstations on ebay or something.
I can't really recommend any DDR3 based workstations, but those would be your best bet for supporting more than a couple drives. There may be a few DDR4 ones that have slipped in your price range.