well said mygoose.... it's not your begginer collector who buys this mahine. Being a single vend is the draw back, but it still looks cool. Not sure myself about how rare they are, as I myself see about 5 a year for sale thru CL or Ebay, yet MAYBE see a RC 81 for sale once a year.
I guess like all machines we buy, pay with what you feel good about, and if you're going to keep it, well, enjoy it! The price you pay is the price you needed to pay to own it.