A buddy of mine built this himself and chronicled the entire process here: BBQ Build . He also did a pretty amazing job on an arbor and the stonework on the retaining wall and bbq area.
I put this out there, because it's exactly the right time for us all to start planning and building our outdoor grill area so it's ready for the summer. I did mine a few years ago: My BBQ and have enjoyed it ever since.
As for mine, when it was all said and done it was between $3500-$4000. My largest expenses om this order were....
2-El Dorado Stone facing
I can't speak for my buddy's, but I know it cost more because he installed a granite countertop (vs. my tile top).
Cleaning is no problem. Obviously, they have a cover for when you're not using it. After each use, I'll clean off the grill....then once every 2-3 weeks, I'll clean the stainless steel using a ss cleaner. There's a tray underneath to catch all of the grease and stuff that you can toss. Other than that...it's pretty minimal. This is my third winter and it has held up beautifully.