Depends on what you're running through it. If you're buying the more expensive match grade fodder, like Eley, RWS, Federal 900, Lapua, Fiocchi, and the like, they all have a bunch of parrafin wax-like lube that will deposit down the bore. Cleaning the barrel will actually remove this accumulation, and may send your first few post-cleaning rounds away from the intended point of aim. Hence, many target and BR-50 .22 rimfire shooters avoid cleaning their guns too much.
I'm in a bit of a pickle with mine, I run a Gewehr98 assembled heavy-barreled 10/22 FrankenRuger, and it LOVES Eley Target Rifle, RWS Target Rifle, and PMC Scoremaster. But it's a blowback autoloader, which eventually soots and gunks up the chamber and action, causing balky operation after just a few hundred rounds. So I clean it, but then I can guarantee that my first several rounds aren't gonna go where the crosshairs say they should, until the bore is properly fouled again.
As for online ammo, I buy most of mine from cheaperthandirt.com. I recently tried some of the Winchester Supreme Match ammo, and it worked very well, definitely sub 1/2" at 50 yards. At $4.90 per box of 50 rounds, it wasn't the cheapest stuff, but it wasn't quite as expensive as Federal Ultramatch, either.