Running ethernet wire is expensive?
At $129 per pop, your network will get OUTRAGEOUSLY expensive in no time with these!
Running wire is inconvenient and a pain, but very worth it. 1Gbps transfer is sweet. Granted I normally only get about 50-60% (60-80MBps) of this theoretical (and it is very likely limited by my HD write speed), but I doubt this wireless would approach even 10MBps.
Take the $500 that (4) of these would cost and pay someone to run the wire for you.