You have a major problem in clarity. I've read even your explanations and still can't quite make sense of your stuff ...
I'm not sure e.g. if the limited size of the customer base refers to the market or to the individual competitors. You don't separate well between properties assigned to each.
limited size
Perhaps:
Most of existing players in such a small market have a limited size of their customer base, so there can't be any difference in
terms of service and pricing among competitors.
which doesn't quite make sense to me, but ...