I'm just finishing up doing one on my own. I can tell you if you pay less than $120 for a refinishing you got a deal. I don't know about the weight reduction. That involves retillering and likely an epoxy coat of the limbs.
MAN! It is near impossible to get a dripless, smooth and even finish with all the curves and edges of a riser. I used to work professionally for a cabinetmaker as the sander/finisher and have done several gunstocks. A urethane finish is difficult (so thick) compared to an oil finish, and the matte finish I am using even more so! I thought it would be easier than a gloss. Not so!
On the other hand, I have not spent a cent on materials - just using what I had around - and it is finally looking suitable. I took great care to leave the original markings and blend in around them. I sanded down my first two coats back to bare wood (except in the marked area). At least that filled the wood pores well. Worst case if you screw up the finish trying it yourself THEN you can send it to a pro. Same price.
I think I would recommend a spray finish. I see in the current Traditional Bowhunter there is an article and his came out pretty good.
You could dip, but how much finish would it take to fill a container that the bow could be dipped into? Gallons?