Concur with the idea that you might do better with Commercial Off-The-Shelf solutions. COTS is preferred if it exists, for several reasons.
1. If the product exists, you'll get your solution faster.
2. If you have to roll your own solution, the hours you spend are a big part of the cost. If you make, say, $25/hour, each day is $200. If you can't make a solution in 5 days, that is $1000. And $1000 buys a heckuva big bunch of software.
3. Typically, if something goes wrong, a vendor will have a hot-line for license-holders of their products.
4. Vendors often allow license-holders to download patches and updates. (Not always, mind you - but often.)
5. If the company name isn't "Fly By Night Enterprises" then they might actually have a reputation to uphold. See if they've been in business long enough to have some web buzz about their products. You can quickly tell if they produce gold or dreck.
6. If you, as an inexperienced person, write this for yourself, it will be code that was written by an inexperienced programmer. Who might not have known what features were needed, nor how to implement them. An experienced vendor, on the other hand, probably has included many customer-driven features, particularly if you aren't talking about version 1.0 of the package.
These are NOT intended to be personally disparaging. These are general principles as to why you might lean towards BUY vs. MAKE for an important bit of business software. As always, it is your business and your decision. But if you really ARE inexperienced, you need to hear arguments about why you would choose BUY vs. MAKE. I've just offered the BUY side arguments.