Old Buick odometer

I have a 1991 Buick Regal with who knows how many miles on it. When we baught it about 4 years ago it had 98,800 or so miles on the odometer. After driving it all over the place for 4 years it now has 99,998 miles on the odometer. One mechanic we took it to said it had a bad cluster which also controls the fuel guage. The guage and odometer are both analog. This sounds like an electronic board of some sort. He said he would have to take it out and send it somewhere to be repaired and would cost about $500.00. Is there any other way to fix this? The car runs great but I’m not sure it’s worth fixing. What do you think?

The best way to repair this is to replace the entire instrument cluster. You should be able to find one from a local salvage yard, eBay, etc. for a reasonable price. Here’s an example, but if it were me I would do some searching and use a little patience; you can probably beat that price.
http://cgi.ebay.com/ebaymotors/1991-91-Regal-Instrument-Cluster-16134864-Gauges_W0QQcmdZViewItemQQcategoryZ33675QQihZ019QQitemZ290192072658QQrdZ1QQsspagenameZWD1VQQtrksidZp1638Q2em118Q2el1247