Yes, after poking around E-Bay I realized that the price for a good used 105mm f2.8 Micro Nikkor (older AF-D) didn't exceed by a whole lot the quote from Nikon for the cost of repair (which was ~$160 USD).
There is at least one extenuating circumstance that does make me prefer a repair versus replacement; having a lens gear that XIT404 very graciously custom made for this particular optic when the stock version was tight enough to bind up the helicoid barrel. The cost of the gear is probably ~equal to the value of the lens.
What I really would like to answer is whether the poor focus sharpness of the 105mm at 1:1 reproduction ratio is due to actual lens damage or is a hard limit of its optical performance? Using the D800 body, I've seen a similar performance issue with an older zoom, but not with any of my other prime lens. Compared to the my 60mm Micro Nikkor (of newer vintage; also focused for 1:1 reproduction ratio and both at f22), the image sharpness is definitely inferior for the 105mm (different depths of field taken into account).
See if can get any traction with Photo Tech in New York. If not, probably down for a newer 105mm f2.8 Micro VR ED optic along with another focus gear.
After several decade of U/W photography, you'd think I'd stop trying to save money at this point...