If you expect to play multiple games, you almost have to think about turf vs natural grass (again, increasing cost). Seriously, I would tell you to look at making the field an 11 man field perhaps with a sixman field inside just to make it economical and open up opportunities for youth (pee-wee) leagues. A natural grass field is also expensive for maintenance (irrigation, upkeep, etc.) and is going to get a beating with multiple game use.
This Friday, we're going to play a team at a field used for multiple youth leagues in San Marcos (they draw from about a half-dozen area communities). I just talked with a HS 6-man coach who is moving some of his home games from there (there are three 6-man high school teams and four 6-man junior high teams using that field along with many youth 11-man teams which use it for games and some practices). He told me that the field is in pretty bad shape just from the overuse even though the operators of the field (a non-profit police league) do the best they can.
Oh, and I'd add an all-weather track and (forgive me please for saying this, but it makes the joint useful in the off season) make it soccer-friendly. Yuck. Now I gotta go take a shower.
Of course, what I'm talking about with stands, facilities, turf, lights, scoreboards, etc. is going to cost a couple million dollars or more. Maybe the folks around Allen ISD have a few bucks left after their new joint ...