did you check out my pics?...both my guitars have them done and I didn't do the one on my Epi...but I did the one on my Strat....70 dollars is a little gouging IMHO...Doug at DMARA guitars (who is a crazy good luth) only charged me 30 dollars for install....um...PM me and I will get with him saturday on seeing how much he would charge to do it.
I wont play a guitar now without a roller nut or graphite saddles (on a fender style guitar). If you combine those with some solid tuners its IMHO of 19 years of playing the most stable tuning guitar you can get...cept' for the Floyd Rose Speedloader.
I might be able to get you a deal if your interested.