If you don't need the server, sell the parts.
HDD cage and hot swap trays are quite expensive, I'd say that's at least about 200,-. I don't think anybody will buy the HDDs (very likely SAS, so not suited for PCs).
SAS cable is not cheap either.
Btw. the controller and trays will run with SATA drives as well. Depending on the soft options, you will have all types of RAID levels available.
Installed is the basic "onboard" controller, too bad.
However somebody might want to buy the server as a whole, these are quite capable, the CPUs are cheap now and it supports plenty of memory. Nice VM server after all...
You might want to look into ILO (If not changed, default Administrator-password is on a sticker somewhere on the case).
There is an extensive BIOS (EFI) setup on startup available, too.