Tennis Scheduling Software

Does anyone have any experience with, opinions on, or recommendations for different tennis facility management software packages? 

I'm looking into software to handle lesson scheduling/billing for our club, and perhaps eventually growing into other areas. If we go this way, we'd probably want to start simply - the easiest first step for us would be to handle lesson signups, scheduling, and invoicing for our 3 pros, and import those invoices into quickbooks. Being able to expand to more features later (e.g. court scheduling, online payment, point of sale, membership management, league management, etc.) and such would be nice, but isn't a high priority. Obviously price is something we're sensitive to.

Looking around, there appear to be lots of packages that claim to do this sort of thing. However, it's not clear that they do what we're looking for, many of them are obtuse on pricing and want you to schedule a sales call, and other things. Any thoughts or suggestions on ones to look at or not to look at would be great.