I bought a number of speedos off e-bay for around $100. If not rebuilt they are not worth too much and their seems to be quite a few around. Rebuilding costs a min of $150 plus shipping. I still have several to deal with becasue they need calibration for one's particular car so arn't worth messing with at this time. The calibration number is noted on the bottom of the speedo. a number beween the high 900s and 1440.
Cheers
Morris