Hard to say.
I bought mine on aussie ebay with the oem transfer pump for $168 shipped and it took me two months to get it. I would guess between $200 and $400
I also know that SOR sells the setup for $900. I thought that was too high and thats why I went the route I did.
You can buy the sending unit from Cdan for $45. I even have a spare because I thought mine was bad.
If your selling the subtank and straps I am sure you would find a lot of interest. Hard to make it work without them.