You could pick up the 105 bits off of eBay or at a swap meet, that are newer versions for that price or less. I did this last year for a 97 R500 Cdale to convert from the RSX it had, save the wheelset which you figured out were not the top end models. A lighter wheelset could be found, too, for less dollars and you could just convert your bike and sell off the 2300. I like the idea of leaving it alone, riding it to train and for errands then buying a new 105 or Rival equipped bike. Your choice, best of luck.