03 RM 125 with extras... good buy?

Size wise your fine with the 125, but if you feel confident in your riding abilities there is also no reason for you not to get a 250. As an adult if you plan to race I'd likely get a 250 just to stay out of the 125 Beginner/Junior classes with all the amped up teenagers.

As for the bike an the 03 was a good bike, my son raced one for a season and really liked it. We sold our 03 RM125 basically as stock (took the goodies off) but it did have new graphics, seat cover, plastic, completely new clutch(basket/hub/plates), top end, sprockets and chain. we sold it at the start of the 05 season for $4000. My guess is that price is a bit high for an 03 at this point. Also if they are trying to sell the excel rims as an aftermarket upgrade, the bike came stock with excel rims. Check out the bike trader (www.canadatrader.com) for your market to get an idea what things are selling for.