Build a lawnbot

I have been wanting to build something like this for years, just haven’t had the time to justify it.  SO I will post someone elses build.  Parts that concern me on this build is the removal of the deck wheels.  I wonder if there is a way to just build off of the deck instead of having a separate frame.  I do like the lights added onto the bot thought.  I was running the costs of this in my head.  Figure $80 for arduino and controllers and wireless.  Another $20 in used motors….batteries are the hard part…$40 at the junkyardin best case.  $40 for the wheels at harborfrieght…frame…well I would have to use makerbar so tack on another $40.  So roughly $250 in materials.  Maybe we could use a self propelled mower instead…

http://makezine.com/projects/lawnbot400/