R15500 works out to £739 in the UK, In the UK they are still available 2nd hand and come up for sale now and again, Normally they sell for between £400-£600 and more if they are .177 and in near mint condition.
I picked mine up pretty cheap within a six month period, all of them are in near mint condition, the SR version is a rifle you either love or hate, i've spoken with guys who love them and have six or more and others who have had one and sold it as soon as they could. Personally i think they are the best rifle Air arms ever made, the director of the Air arms company told me himself that they were the best rifle they ever produced and are "something else".
This is my SR:
Mk2 action in .177 calibre fitted into an NJ Custom stock, the wood is Hyedua not walnut.
I originally owned this one about 15 years ago and foolishly sold it to a local collector, I paid £450 to get it back from another local shooter after the collector passed away and his guns were sold on.