Where to buy a suit: men's boutique or Men's Warehouse (or other chain store)?

I’m looking to buy my first suit and money is in an issue. I would like to get a suit that looks really good and fits perfectly in a basic charcoal/grey color that can used for many occasions in a semi-conservative style, so location shouldn’t be an issue. What it comes down to is service and price. A local store has incredible service – providing information without pushing me to buy anything and they sell products that seem to be built well, but don’t have the name recognition of the brands you see at other places. Also, this store would be selling a really good first suit (economically priced) for a little under $400 – other places would be selling TWO suits for about $100 more.

What should I do?