Donnie — Whether they take more money to maintain is a complex question.
One needs to look at total square footage and the use of tees. There is also the flexibility that a greenkeeper has in shifting play to allow a tee to mend. And, there is the complex issue of marketing and return play — if a resort course did not have multiple tees it is likely that very low handicap players may find it "too easy" whereas a weaker player may find it a course not worth returning to. And, for women and kids, the same holds true.
In the case where there are not enough members or people playing because they cannot find "their" skill level, then — yes — it will be expensive to maintain. But, when design decisions are balanced with those of the financial and marketing, I think flexibility in tees can be a good investment.
Tees, by the way, are a nominal maintenance item. Yes, they have associated costs, but not to the degree of some other features. Tee maintenance is a matter (mostly) of square footage. So, if we design a small mid-range tee on a par-4 — let's say 325-yards — we might keep it very small, perhaps only 800 square feet. This lessens the required square footage of a main tee by a small amount. So, maybe we are close to even had the tees been larger.
At 300 golfers per day at a recent course we completed, it is essential that we mantain enough tees — and have teeing grounds to accommodate a range of player types. The alternative is to mandate play from just a few tees (2) and live with the reality that a novice player or very, very elderly player may not be able to carry to the fairway or will make 5-6 strikes to reach a par-5. At one hole on this layout there is more than 140-yards from back tee to forward tee on a par-5 into the wind. Play can be significantly speeded when we offer multiple tees at clubs/courses that will have a variety of player types. The course I mention is one such course.