At least at my DD's high school, numbers, rather than money, has been the reason her h.s. has not had a freshman team for years. Varsity coach is expecting h.s. to have a freshman team this year based upon the number of 8th graders he instructed the jr. high coach to keep on last year's jr. high team, and upon turnout at this year's mtg. about winter league and open gym.
DD's h.s. is a decent size D-I school, but I think they will always have trouble fielding a freshman team; and in some respects it may be because of the opportunity girls have to play summer ball. At least at DD's h.s. the gap in talent between jv and varsity is huge; and alot of the girls think if they don't play summer ball or otherwise see themselves making varsity by their freshman (or at least their sophomore year), they don't bother playing at all. For example, at the mtg. about winter league and open gym, DD overheard 3 freshmen talking that if they don't make varsity, it's not worth playing. She didn't tell them that last year's varsity team only graduated 2 seniors because she knew they might quit right there because ?last year's jv team went winless (not fun) while the varsity team won conference (going 13-1).
Also, at DD?s h.s. at least, it would seem that numbers tend to support the conclusion that you?d better make varsity by your freshman or sophomore year. Of last year?s 9 starters on varsity, only one did not make varsity until her jr. year (and 5 were starters since their freshman year).