As an IT consultant and small business advisor, I generally recommend going with a canned program vs getting something customized. I say this both as a former app programmer, a business owner, and an IT geek.
You're right: you get exactly what you want and how you want it.
The drawback is that you're stuck with it and every single extra feature beyond the basics has to be added by you. Want detailed A/R reporting? Build your own. Marketing lists based on zip codes? Build your own. Integrate the accounting package to feed into Quickbooks so your accountant can look at it? Build your own.
If you have the fast, expert experience, this isn't terrible...but ultimately it takes the owner AWAY from his/her primary responsibility: growing the business and not the support systems. Every hour you spend developing your application is an hour you'll never get marketing, selling, or shooting. Those are the only three things you'll do that generate income.
I know some businesses doing just fine with some good Excel spreadsheets and integration with Word. That's all they use while generating $1M worth of business moving product. If it works, great. I know others that have $100,000 database systems with a full time programmer and only $750,000 annual income. They feel they need it. Okay, if that's where you want to put your money.
QuickBooks will do the basics and costs only $200 for both Mac and Windows. Depending on your margins, that's easily earned in a few jobs or a wedding. The products I linked above are higher priced...but tailored specifically to a small studio environment. You pay extra for that but in many ways, it can be worth it. I know I wouldn't do a school shoot without StudioPlus at this point. Tethered shooting, database tie-in with student IDs, barcode scanning, and easy interface turned a 25 student class into a 15 minute experience. We actually had teachers complaining because we were too FAST!
