I can only second the experiences of many folks here. My LBS has been very supportive and pleasant. It is well worth some shopping around to find an LBS where you feel comfortable and appreciated as a customer. MY LBS and I have been learning together what components work best for a large rider. Their advice has been very good and I've been really pleased with everything they have done so far.

I will add that I did not go in to any LBS with a bad opinion. Bike specific stuff can be very overpriced -- that is just a fact in the market. A good LBS can add a level of service and expertise that makes the price worthwhile. My only complaint with some LBS is their attitudes toward newbies or non-racing type riders -- condescending or patronizing covers some of it in other cases it is just polite indulgence since you might spend some money.