I don't know about the MBA to be honest, wouldn't mind a look if you could post a link though.
I suspect that it requires significant PM experience to complete though. I am a PM, a proper one; running projects rather than being a member of a project team or a junior PM, I have full budgetary control and autonomy on all my projects answering to the project sponsor, I'm not sure I have the type of portfolio required to complete an MBA.
My feelings are that you probably do have the commercial accumen just not the experience; which an MBA isn't going to give you. My tact would be to follow the APM route : APMP then Certified Project Manager + Risk certificates, it may seem tedious but is a well recognised route and with APM currently seeking Chartered status all of their courses are going to count towards Chartered PM. MBA's are priced for companies to pay for and reliant on the drawing down of grants and subject to tax relief, if you can get a job as a PM your company may well put you through the MBA.
Industry is short of PM's at the moment at all levels in every sector, APM is the industry standard and pay with just an APMP is between about £35k and £60k, little additions like PRINCE2, perhaps a strategic PM course etc can make you stand out but ultimately a decent portfolio of "Projects" as opposed to projects that don't stand out from everyday business will secure a good job. Companies want you to be able to plan, schedule, analyse, calculate earned value and IRR, do a stakeholder analysis, formulate a communication plan, measure and present risk appropriately and all that other important stuff, but what they are really after is people who can lead a team, communicate well and make decisions whilst meeting their constraints - all things that come with experience rather than study. Some aren't particularly worried if you have no sector specific quals: engineering, IT etc, their clients want a structure PM approach from a qualified and experienced project manager because it significantly reduces their risk. I'm not sure an MBA is of interest to them when recruiting but they might see it as a benefit to subsidise your benefits package and form part of a PDR.