I just bought my second bike in the last couple of years, neither from my LBS. I was in a very similar situation to yours. I'm in my mid 30s and hadn't ridden seriously in years. The first bike I got was a cheap single speed off Amazon (Takara Kabuto) for around $200. I assembled it myself, then later swapped the brakes, handlebars, pedals and tires myself. I had never done any tinkering with any of the bikes I owned in the past but I found most of those things to be easily done on my own by watching a youtube video or two and reading Sheldon Brown's site.

After starting to commute and riding every day I knew I wanted to eventually upgrade so I decided to strike up a relationship with a LBS that a coworker recommended. I bought some new 700x38 tires from them and paid them $50 for a tune up (which seems ridiculous for a single speed). I bought a few other cheap accessories and when I was ready to start shopping for a new bike it's the first place I went. Even though I had been there 4-5 times in the past couple of months and did business with them, they didn't remember me (point deduction for the LBS whose main selling point is personalized service). I explained exactly what I wanted in my next bike and they immediately put me on 3 different "bike store brand" hybrids because that's what they had a lot of in stock and want to sell them and they had nothing in stock that fit what I was asking for. They fit me by just looking at me and asking how tall I was and putting me on some bikes. I knew what I wanted and they would have to special order it and they were quick to tell me if they did order it I had to pay up front and there was no returns if I didn't like it or it didn't fit right.

Recently the bike I wanted went on sale at REI for $300 less then the LBS wanted to charge me so I bought it there. While I didn't get a professional set up on the bike to get the fit right, I saved a good amount of money which I am going to take and buy a Kilo TT off BD to replace my single/fixie that is a little too big for me and has cheap components that are starting to fail after a couple of years.

I support "the idea" of the LBS but unless I feel like I am getting personalized service and advice, I can't see why I would pay a premium on everything.