I hate to say this, but at your age and stage in life, the MBA degree isn't the key - it can be helpful, but not as the *one* thing that will solve everything. Brands matter to kids. It becomes far less important the older you are (and the older you are as perceived by others - and your resume will give your age away since you'll have your college grad year on there).
Also, you are making a career switch - I get a sense that you're not completely prepared for what it will take. At your age, it's going to take more work because employers will be more skeptical about your willingness to "start from the bottom" just like all the other kids in their mid-20s (and that's assuming you're willing to start over - it'll still be an uphill climb to convince recruiters that you're willing to). The MBA isn't really going to solve that completely.
My suggestion is rather than look to spending more time, effort and money looking at b-schools, you really should focus on getting a full-time job or finding a set of responsibilities that keep you preoccupied on a full-time basis (i.e. volunteer for a political organization, etc. on a full-time basis, help a friend start a company, etc.). At this point, school should be a *complement* to what it is you're doing, and not the "way out" of your predicament. I know that is hard medicine to swallow especially in today's job market, but it's really your only solution (not to mention that adcoms to be blunt will find a 35-year old unemployed engineer unappealing for b-school admissions).
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