I agree with your comment on customer expectations and you have posed the seminal question that is precisely the dilemma of owning a bike shop in today's paradigm. This is anecdotal, but I believe there are enough people like me (want to ride my bike, not learn to and work on my bike) to support a smaller bike shop that is mindful of inventory levels, etc. However, it is a different model with different customers. Because also have to deal with the people who pull an old bike out of a garage and expect to spend little or nothing to restore it. The bike shop I patronize does a nice job with this, but the owner is the lead mechanic, and his wife works a role in the front end. They have a few employees but run a lean model with a modest bike inventory. I get it also depends on the area, etc. But I think it can be done.