I have been researching this myself after discovering that my trusty HP PSC 1210 apparently lacks a driver or something that prohibits it from working with my new Apple Airport Express (though it works just fine if I hardwire it into my Macbook, but that would defeat the purpose of the wireless network).

Anyway my budget and requirements are pretty similar though I definitely want an all-in-one to replace my 1210. After doing some research and receiving a ridiculous "trade in trade up" offer from HP I have concluded that the HP OfficeJet 7310 is probably the best model for my needs. It is currently on sale at officemax for $199 (reg. $399) which appears to be a good price compared with comparable units. The HP website claims that the unit was tested and and supposedly works with an airport. The unit took some early hits from CNET reviewers but the later reviews are mostly good.

I am not too thrilled about replacing a perfectly functional printer but I've gotten good mileage from it over the last 3 years at an orig cost of $90. And no doubt can get some $ for it on craigslist or a nice donation receipt.

My advice to you would not to be penny wise and pound foolish by getting a cheapo printer that won't work with a wireless network as you will probably want one that does before the next one expires.

P.S. For those who care yes I have been through the Mac and HP support boards and various message forums - have tried about a 1/2 dozen fixes but none worked.