If you think you'll be cutting mostly text or designs that were provided to you, then SBE will work just fine. It looks a bit dated, but it's more than functional for cutting.
If you think you'll want to do more design work on your own, then Corel or AI would probably better. Do not discount Inkscape, it's great program, and it's free.
If you're not sure what you really need, then stick with the free for now, until you get a feel for what you actually need before just plunking down some money.