The .22 caliber Benjamin Discovery($400) makes a nice small game air rifle.
http://www.pyramydair.com/p/benjamin-discovery-air-rifle.shtml
The $400 includes a hand pump. The Discovery should give you 35 shots at around(800fps to 835fps with 14.3gr pellets / 20-22ft-lbs)** per charge
**Tom Gaylord did report a string of 25 shots with his .22 caliber Discovery that averaged 856fps with 14.3gr pellets(23.3ft-lbs) >That's pretty impressive for a $250 PCP
The Discovery is accurate enough and powerful enough to make clean, humane kills on small game(rabbit, squirrel, etc) out to around 50 yards.
If you wanted to go just a bit higher, for $599 you can get one of the most powerful(65ft-lbs), high quality .22 caliber air rifles that I know of. The Evanix Hunting Master AR6
http://www.pyramydair.com/p/evanix-ar6-hunting-master-air-rifle.shtml
The $600 is just for the rifle, you would need to add a scope and pump>or HPA tank
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Added:
Benjamin Discovery vs Marauder
Marauder - for one thing you can't just take a manufacturers "claim of - up to maximum muzzle velocity-" then plug in any weight pellet you choose to come up with a "pipe dream" muzzle energy
The Marauder does have a much nicer trigger, along with some interesting technological advances over the Discovery and a 10rd magazine compared to the single shot Discovery ,but what it is not is significantly more powerful. The .177 caliber Discovery is around 19-20ft-lbs the .177 caliber Marauder is around 20-21ft-lbs. And while I don't have good numbers(chronograph) for a .22 caliber Marauder I can't see the performance just taking a wild leap forward, not when you're taking about the same powerplant for the .22 as the .177
Even "IF" the .22 Marauder did get 30ft-lbs of muzzle energy(fat chance) >It "might" top out at 24ft-lbs. It costs twice as much as the Discovery. Heck the .22 Evanix AR6(65ft-lbs) only costs $100 more than a Marauder, and it's a time tested high quality rifle.
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Later:
I see that "someone" found the TD button, but forgot to include a good(reliable) source showing the Marauder at 30ft-lbs
Tom Gaylord - one of the foremost airgun experts
http://www.pyramydair.com/blog/2009/06/benjamin-marauder-part-5.html
His article shows a 50 shot string(chronograph) for the .177 caliber Benjamin Marauder. The high water mark is a reading of 952fps with 10.5gr Crosman Premiers or 21.1ft-lbs
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Hammerli Pneuma - This will allow you to compare specs, side by side
http://www.pyramydair.com/cgi-bin/compare.pl?models=1796,1543,1774,942&model_type=models
As for the Pneuma, Straightshooters.com is very high on the rifle, and they're a fairly tough bunch to impress.
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"J Kirsch" has informed me that the Marauder does come with an adjustment tool that allows the user to set the power level high enough, so that the rifle can reach a muzzle energy of 30ft-lbs. So I stand corrected.