Personally, I think most of the people nowadays would at least have a diploma (Most of my colleagues have degree cert), the working world is getting more competitive nowadays. If you want to be ahead of others, getting an MBA does more good than harm
MBA will definitely make you stand out (among other diploma/degree grads) and the chance of you get promoted is higher, hence salary is of course higher

I've a friend who performed worse than me in high school but her family is rich and afford sending her to study Master in SIM (one year).
Her entrance salary is already higher than what I get now - We're at the same age, the difference between myself and her is only the master cert (I'm a degree holder).
About the two options, I'm not sure what to recommend as you didn't mention which is the more prestigious/less prestigious academic institution.
Good luck and all the best!