there are some nice vintage tachs on Ebay for under 100, but this NOS one is going for about 1200

http://www.ebay.com/itm/NOS-Shelby-vintage-Sun-Super-Tach-SST-802-8000-RPM-NIB-NOS-NC-5-chrome-cup-/262348176007?hash=item3d152b7a87:g:m2kAAOSwpDdVNwwR&vxp=mtr