The price you paid was lower than market for an original Trek 5200 (asking prices are market between $500-$1000, depending on the Seller and how long you want to wait for a Buyer). Probably due to the strange combination of components. If I were you, and that bike was mine, I'd probably strip off the non-matching parts and install all Shimano 105 or Ultegra components. You can eBay or craigslist the odd ball collection of parts that you remove piece by piece to recover some of the cost of the replacement matching parts.