What are some concerns I should be aware of?

Hello, 
Thank you for your question. I will answer the easy questions first. Orbera is one Balloon. Reshape is a double balloon. Obalon consists of three balloons inserted at two weeks intervals. None of them dissolve. In my practice, the balloons cost $8,000 and I do offer a package that includes reinsertion over the course of a year and a half. 
As for concerns to be aware of. My opinion is that the most important question is whether you are a better candidate for gastric sleeve. In addition to not demonstrating the long term benefits proven in studies on gastric sleeve and other bariatric surgeries, the balloons do no have the same immediate impact on blood glucose levels (diabetes) as the gastric sleeve and gastric bypass surgeries. Also, if you are to undergo multiple balloon insertions, it is likely more cost effective to undergo surgery rather than balloons. 
Whichever you choose, it is essential that you have a weight loss team complete with a dietician, emotional and psychological support, and exercise plan.
A Skype consultation with a bariatric surgeon will answer your questions and help you determine the best treatment for you weight loss goals.
Best wishes,
Dr. Moein

Balloon is an option for patients who looking for a temporary tool and do not want to have surgery! 
Average weight loss is 30-50 lbs and it’s FDA approved for BMI 30-40.
 What is the cost? The cost is $8,000 in our program.
How many balloons and why? Orbera is one Balloon, Reshape is double balloon and OBalon requires 3 Balloons places in two weeks interival. Why? Because they are designed that way...
Does the balloon resolve? No. In all the three types, balloons have to be removed in 6 months for safety reason, through endoscopy. Eventhough you could potentially get another balloon in a later date, that is not the idea, as you are supposed to have learned to keep your weight down, and that will cost you additional $8,000.

The main problem with the gastric balloon is that they have to be removed (they don't dissolve) after 6 months... after which you will regain all the weight you lost.  They aren't supposed to be replaced every 6 months.  The idea is that you kickstart your weight loss with the balloon, and then go the rest of the way on your own.  The problem is that this strategy rarely works.  You could come to me and get a sleeve gastrectomy for $11,000,which isn't much more than a balloon, and be done with it.I see patients regularly who have wasted their money on the balloon, only to regain the weight and then realize that they should have had the sleeve in the first place.