The 228R isn't all that rare nor that special. What the 228R is however is a German 228 slide mated to a 229 railed slide. They were produced after SIG discontinued the standard 228 and introduced the 229 in 9mm. SIG more than likely had a bunch of left over 228 sildes and created the 228R. I don't know what they cost but I reciently picked up a really nice W. German 228 for just over $500.00. So they are out there.