I use a D-Link 614. It just plugs into the back of our modem outlet. It's been sitting happily broadcasting away for about 18 months with no problems at all. You'll need to plug into it at first, to set it up, but it's pretty easy to do.
We've got 2 laptops, a Tower and a wireless printer all working off it and these devices work anywhere in the house.
Dunno about prices and I don't know what the rules on pprune are about mentioning suppliers but the place I got ours from has something to do with fingerprints...
Cheers,
TOO