As a number of posters have pointed out, I have always been willing to pay a bit more for a given item if I feel that I am getting value added for the extra expense. That being said, when it comes to my trains, I don't have a problem. I really don't have a "LHS" per se, but I am very fortunate to live close to Grzyboski's (which I would classify more as a Train Store). I'd say 95% of my train dollars are spent there. His prices are always among the best available, and for me, no shipping charges magnified by instant gratification
I have (knock wood) only had one DOA issue, a bad Fastrack switch (out of about 16 purchased). When I brought it back, Joe saw me walking in with the box under my arm, asked "bad switch", I said yes, and he got me a new one. When I needed one more O-72 wye and he was out (apparently I had bought out all he had), he offered to pick one up for me at one of the Allentown shows that weekend, and he didn't charge for the extra service.
While Joe apparently doesn't have anyone in house to do repairs, he does have someone he sends them to. I had two engines with issues, one of which I fried a major board because I hadn't yet installed fast acting circuit breakers for my PW ZW transformer. The service was excellent and reasonably priced. Both engines were returned in excellent condition and fully operational.
As I said, I consider Grzyboski's to be more of a train store, they are rather light on the scenery material side, specifically in Woodland Scenics items I was interested in. For those items, I need to go to the internet. Luckily, another forum sponsor, Nicholas Smith, has an extensive inventory, good prices, and his shipping is quite quick to NN Pennsylvania.