Just slap in a SCSI HD upto 1GB and populate the DRAMs to 2MB (make sure you have Rev 7 ROMs) and you are all set! I have the Rev 7 Roms if anyone is interested.
I have a 1GB SCSI HD and it runs awesome under AmigaDOS 1.3
I would say around $50 is a fair price, now if it was MIB and not yellowed I would say $130 or so (Thats what I paid for mine MIB)