How about on the next shoot, you "accidentally" let one of those pieces of jewellery fall in your pocket, then after a quick trip to the Cash Converters you can buy all the gear you want

Or for a more legal suggestion, try getting a Zeiss MC Biometar 80/2.8 for Pentacon Six mount ($100) and a P6-EF Tilt Adapter ($100), and a set of Kenko Extension Tubes ($100), you can do all that you can with the TS-E 90 and spend the extra cash that you save on lighting, strobes, backdrops, etc, like others have said, that's more important than the lens in a lot of cases.
(or the MC Biometar 120mm f/2.8 is sharper, but rarer, 80mm are easy to come by)