The Whiscombe air rifle looks probably as good as it gets for air rifle technology. The JW80-FB MKII specifications and independent accuracy figures are excellent. The price of this make of air rifle $1670 is very expensive though and at the end of the day a much cheaper rifle could be had and when considering the markmenship skills most have, most people wouldn't be able to shoot any better with this expensive rifle. If fact a cheap chinese made QB78 or QB79 for around $90 would suit most. As you have pointed out the cost of the Whiscombe is similar to a Anschutz .22LR. this is not down to any firearms law restriction, this is because at the end of the day the Whiscombe air rifle is just a precision rifle in much the same way the Anschutz is.

A comparison against a tuned QB78 and an Anschutz 1808 .22LR over 25 yards can be found here ;

http://members.fortunecity.com/airgunclub/qb78index.html#test

Its not a very refined air rifle and quality varies but if you get a good one it is a bargain.

As you can see the groupings for the JW80-FB MKII they are superb up to about 50 yards then begin to get a lot poorer. This is just down to the nature of the balistics of the air rifle pellets. As can be seen at 80 yards the groupings are now about 1.5 to 2.0 inches. I would expect the Anschutz .22LR to be much more accurate over 50 yards to 120 yards. At around 150 to 180 metres the Anschultz would be all over the place. Good quality air rifles are certainly as accurate as .22 LR rifles up to around 25 to 50 yards. The differences between them would require some exceptional markmanship skills to tell them apart at the other end of the range. Discussing groupings takes me back a few years when using the old Lee Enfield .303. I used to be able to get 4 inch groupings with just the iron sights at 200 metres when I was a teenager.