Hey all,
I'm new here, only recently discovered these amazing devices, and just got mine in the mail a few days ago! I got the mega

I wasn't sure where to post this, so i am sorry if this is in the wrong forum.
I am interested in sending commands to the arduino via wifi, which could also send back information if required.
Now here is the problem:
These wifi modules are so expensive! I saw a wifi usb dongle on ebay for $5, so i didn't think that
the module for the arduino would be really expensive. The reason as to why i want to go for wifi is the high bandwidth.
Why are the modules so expensive? I saw a module for $90. Unless, i am looking in the wrong places then lol?

So please, point me in the right direction if i am, and also other alternatives, (hacks etc on a wifi usb dongle perhaps?) to accomplish my task.
Thanks!