I'm not saying you can't find a good deal online but I would think that finding a good buy on one of these locally would be the way to go. The freight on a garage door would likely be more than local sales tax. I've looked at quite a few brands and think that Martin makes some of the better garage doors.
I ended up getting a Clopay from Home Depot. Since they don't charge tax if you get it installed (something about it being a permanent part of your house), is was actually a few dollars cheaper to get it installed than to do it myself.
I've checked on local vendors. They're consistantly around 1500.00 installed.
I wanted to check selection and cost online to see if there are any benefits.