It sounds like they're yanking your chain for the labor on that speedo, and that's absurd. I did the sensor and o-ring and it still weeps a bit. I talked to the man, Marlin himself about that, and he said sometimes the surface is too smooth and the o-ring can't really "grab on" to anything, let's a little bit by and you have a weeping problem. He said I could scuff the surface with some fine steel wool, and dammit, it helped! I didn't go crazy, and started with "0000" and barely did some scuffing. I plan to do it again, and use the same 4-0, but take my time and cut it a bit heavier. My goal is to eliminate the problem. I purchased the sensor as it was leaking through the body. That was $230 iirc at a hook-up price from the dealer, and the o-ring was 2 bucks iirc. Took me an hour start to finish and now barely weeps. Next time I'll grab another o-ring just to be safe, and see if I can get even better results.
Fwiw, my rig is a rust free 96, 175k/mi at time of purchase almost 2yrs ago, lockers, and I paid 5k. That seems to be the going rate in the greater Sacramento CA area, 5 with lockers and 3-4 w/out. Some are higher, and they're unicorns. Many lower, and they're turds. I've seen a lot of beautiful ones out of Lafayette CA (east of east bay (San Francisco area)) that are of the unicorn caliber, and they range from 4500-8500. The best ones are the soccer mom specials with 100k/mi, lockers, two-tone (sp.ed.?) and all the options. Easy to look at addresses on Maps and see what type of community the owner lives in. The latrer mentioned city is yuppie-ville, houses range from 400-multi millions, so the people typically take good care of them. I'm bored, I'll go see if any are up for grabs. If I find something I'll def post it, even if it's just for comparison.
P