Most providers will offer a package which can be negotiated. The cost of mine included 2 years unlimited fills and aspirations, and 2 years surgical cover. Had I pushed harder I think I could have increased both to 3 years, but you live, you learn! Top Kat bought an insurance policy with her band - I wasn't aware of them when I had mine fitted, but if you do decide on a band it's worth bearing in mind.
I would call a couple of providers and see if you can book a free consultation, either by phone or in person. In the meantime have a good read on here and google the differences between different types of bariatric surgery so that your discussions with providers are informed discussions.
A band won't physically stop you from snacking, nor will it physically stop you eating cake, it will just make you chew that cake carefully and eat it slowly! Only you know whether you will be able to make the big changes necessary to work with it.
Good luck! x