The other option is to find a beater 50/2 AI. Take the aperture ring and the lens mount assembly, complete with rear element baffle (if the AI lens has five mount screws, otherwise, only the rear element baffle), and mount those on your pre-AI K version 50/2. Turns your pre-AI lens into an actual AI lens, except for the focusing ring grip and the serial number. Quite a few of the K-version Nikkors can be AI'd in this manner, making a more-complete AI conversion than what you can get anywhere else.
That said, if the AI conversion is being done by the guy who I think it is (microbee on eBay), you'll be pretty satisfied with his work. Had him modify my 28/3.5 so it can be used on my F4 without breaking said camera.
Re: 50/1.8 Nikkor prices, one of the local shops here in the Seattle area has a pretty nice long-nose AIS version for $89.50. Much less than what you're expecting to pay for one.
I'm not sure if this helps, but I would leave it alone and shoot it on a camera that does not require the modification, like a plain prism F2. On which camera are you planning on using it? Do you have a hand held meter? My 50 1.4 non-ai is a dreamboat and I use it on my very old F2 - works insanely well and is such a nice lens. Sorry, blah blah blah.
I realize that I'm new to posting here, but I thought I'd weigh in on my experiences.
First, I've never had an Ai conversion done by John White. I've heard his work is good.
I have had some work done by "microbe" - Brian Williams. I had him perform an Ai conversion on my 135 2.8 K and 200/4K lenses - using the factory Ai conversion rings that I bought. Both lenses came back to me working flawlessly.
I currently own the following Ai'd lenses (all K lenses that have been converted with factory rings):
28 3.5 (mostly used with my D200IR)
I'm not a big fan of the grind-and-tape method of Ai conversions. I always try to find the factory rings. But lately, these are becoming scarce. Check out Koh's camera, Pacific Rim Camera, and Crystal Camera Repair. They might have the correct rings you need. Best of luck with your search.
My recommendation is also to use an F2 rather than mess with the lenses. When you get an Ai or AiS model then you have the best of both I guess.
I shoot a FT2 Nikkormat that the lenses are used on. I also shoot a N80 with AF lenses. My 35mm F2.5 ai shoots on that AF body with hand metering (big whoopee do) but the 50 does not. I just need a 50 lens for it and I'm basically set. My 50 blows the hell out of the F1.8 AFD btw. There may good ones and bad ones but my new one was dog dirt.
[QUOTE=waynecrider;1518492]I've got to say I'm a little over the older used stuff for now, especially in bodies. I also had to return a lens not long ago to a store and while the problem was reimbursed no problem, the quote "Ex" bargain I thought I was getting was not so Ex. Best to buy the best there is and figure old is old, so matter the appearance.
These days, buying anything, even new gear without actually laying your hands on it can be a real crap shoot. That's the primary reason that I buy factory refurbished whenever I can because it assures someone at the factory went back through it and fixed what they didn't fix when they built it. Plus, it still comes with a warranty and a cheaper price tag while working better than it was new.
OTOH, when I score something used, I go an outfit I can really trust that I know isn't going to try and rip me off, run away, close shop and split to a foreign country and will stand behind or at least next to, what they sell. I've dealt with KEH.com and never ever had a single issue that they didn't address promptly and that was only twice in twenty years of buying and selling through them. When they grade something, it's always under graded. I've found for example, their bargain grade is what anyone else would consider good to very good. And their very good is like new.
Dealing with a reputable outfit takes a lot of the risk out of the deal, no matter who the seller is. Waynecrider is absolutely right. You tend to get what you pay for and while I hate to say it, these days, no matter what you're buying it's still the old adage "Buyer beware" and "If it sounds too good to be true, it probably is."
Places like KEH provide solid guarantees on all their used equipment. They'll either fix it or replace it with something comparable, take care of return shipping and do it quickly. They have an in house service department. And you have to remember too, commercial resellers like KEH are in business to make a profit and have an overhead to pay for. I don't mind paying for quality a little bit extra for used gear if I think it's going to be reliable and do what I need it to for a reasonable time after I get it.
One other thing, is look for used equipment at authorized repair shops. David Odess is a Hasselblad repair guy and he sells used gear that he warranties. Midwest Photo Repair in Michigan is a Nikon Repair Center. And they sell used equipment, bodies, lenses, etc. Very excellent outfit for Nikon repairs, also warrantied fixing.
Drop the dime(s) and pay a bit extra. Bargains often break your heart, waste your time, cost you money and have you ever known a piece of equipment that didn't break at a really bad time?