You shouldn't have to spend anywhere near $800 for a modern lens, with clean glass in a properly working shutter, that will cover - $400 is more like it, particularly if you don't mind a bit of wear on the barrel. Look among the slower (f/6.8, f/8) wide-angle types in the 90mm-125mm range, toward the longer end if you want to go whole-hog with movements and minimize the need for a center filter. Fuji, Nikon, Rodenstock and Schneider all have modern wide-angle offerings in that range. Rodenstocks can often be found less expensively under the Caltar II-N label, Schneider Super-Angulons under the Caltar-W II label. The lenses Fuji and Linhof have offered with their 617 cameras are all just LF lenses mounted in focusing helical; any existing 617 focal length that interests you from either vendor is also available as an ordinary LF lens in shutter.
(Is that DNA or RNA polymerase? Or can you switch-hit? )