Cost on clay courts is $13 daytime and $9 evening each for 4 players for a 2 hour playtime. Hard courts scattered around TV are free. The staff at Glenview will put you in touch with groups looking for players or subs at your level for both Glenview and Lopez. The Rec. Dept can give you info on leagues playing on the hard courts. Leagues are formed 2 or 3 times a year but seem to always be looking for good subs. Watch the Thursday Rec News publication for the schedule of "Mens Open or Round Robin play" times. The level of play is usually lower than 4.0 but a few better guys show up for some practice hitting and social play. Talking with them should get you into some good tennis.
I've been a part-time Villages resident since 1996 and have never been at a loss for 3.5 - 4.0 tennis subbing as I come and go. I just e-mail a bunch of group leaders with my schedule and I'm in for the duration of my stay.
As an aside, early morning and evenings are a great time to play in hot months. I find evening especially enjoyable if you can adjust to the lighting.