Frankly, with all of the job experience on the OP's resume, a degree mill is not a bad way to get a legitimate line on the resume. I had an associates degree, went to the local branch of the state university, and realized I'd be graduating with my kids if I stuck with that route. I sucked it up, plunked down the money to buy my degree in 15 months worth of classes, and now HR departments everywhere will pass that portion of the resume filter.
As far as the original requirements - fast, cheap, accredited, you may pick any 2.
One way you can lighten the financial burden is to get hired full time by a company that offers tuition reimbursement.