MBA is nothing if you dont know how to use knowledge or havent developed right set of skills for business. A lot of MBA students know theory, but when they are given tasks, they cant do anything, because they dont have any experience. If someone thinks, that after getting MBA, his company will be more successful than other on the market, then such person will be surprised to find out that market is rules not by the level of diploma, but by people.
agreed MBA doesn't really help if we never have the chance to try out a business, there are plenty of MBAs out there that getting the degree solely for getting career improvement to say that getting MBA for the sole purpose of starting company might just seem to be a mundane action.
I think its better to start out the business first, figure out how the market reacts to your products, see whether your business can have the opportunities then get the MBA later on.
MBA can wait, but building business usually you don't know whether you gonna gain success or not, though if you can do both at the same time its gonna be enough I guess, even right now there are many MBA online programs anyway, its easy to get.
its only become urgent if you really need that MBA to maybe apply for a higher position job. otherwise seems like a waste of time and money from my opinion, i mean thats just my 2 cents.