I thought the homeplug support allows you to connect your receivers together through the Dishcomm feature via your power lines (ac plugs) - and if you are able to connect them both successfully with the Dishcomm feature, only one of the receivers had to be connected to the internet? You wouldn't need any wireless feature if one of your receivers can connect directly to the internet. That receiver would then connect to the other receiver through your ac plug using your home ac wiring. Then both would be accounted for and you wouldn't get the additional outlet fee.
The way my house is wired, though, doesn't allow for the Dishcomm feature to work so I do connect each one of them to the same router. However, my question is if it would be okay to have each receiver connect to different internet providers. No tricky stuff here - I just happen to have cable internet near one receiver, and DSL service near another receiver. I haven't done that for fear that they would think that it would seem that the receivers were in different houses, but honest - they're not. It just would be more convenient for me.
Jim5506 - what do you mean by your comment? I do not get charged the $5 additional outlet fee with both of my 722s on the internet, but when I did not have my older receivers (used to have two 301s single tuners) connected the phone line I was charged the fee.