I wouldn't completely discount an eMBA, and the Queen's program has a good name in Canada. I don't completely disagree with what DaFonz is saying, but I would consider the following in a bit more detail:
1. I don't think that you're out of your league, based on what you've written. One of the neat things in professional programs is that a cohort is selected for diversity. Business, as a whole, is not the toughest subject. You sound polished and with experience managing 50+ staff, you'll provide good company. (In fact, I'm soon looking for someone with strong retail operations background and an MBA for my team, and I would place value on someone who has been at the front lines for a bit.)
The only question is whether you have the smarts to compete at the end of the day instead of dragging the class down. I have an acquaintance who struggled in school and on the GMAT (couldn't crack 500) and graduated near the top of his MBA class. I have another who was a B student at best and she ended up gold medalist at Ivey. You can surprise yourself (and business theory is common sense, for the most part).
2. Average age is just that, 'average'. Given the small size of the Queen's class, the average can be pulled up significantly by a few mature students. Case in point, on those Queen's profiles, how many of those photos appear to be of people who are 38? I know people who have been accepted to the Queen's eMBA in their 20s. I also happen to know that the ages in the Vancouver programs tend to be polarized - a big chunk of the cohort is younger than the average age of 29, and just over a handful are very mature (well into their 40s and even 50s). That said, I agree with DaFonz in that you'll have to think twice prior to spending the $90,000, but I disagree that a school just wants your money. The programs look for much more than money - they need satisfied graduates to ensure a thriving alumni network (donations, rankings and prestige). I'd say, they wouldn't mind your money, but there has to be a return on investment for them also.
3. I disagree that you should aim for a Bachelor's if an MBA is in your sights. I'd take the quickest route there. I don't see a few more years and an Athabasca BA doing anything for your profile that your experience + a kick ass GMAT score wouldn't show. Many Canadian programs will make exceptions, even though they don't publish that fact. I've seen Rotman and UBC do it in the past, even into full-time programs. Once again, exceptions are not the rule, and you'll have to demonstrate something special, but there is possibility here!
4. If your direct 2 year opportunity cost is $250K, you might be making well beyond the salary expected by a fresh MBA grad. (In Vancouver, that is between $60,000-70,000 for the most part, rising to about $85,000 after 3 years. Again, that is just an average, and the range is wide, but we are not a city that values MBAs much). Now, if you are projecting opportunity cost with interest and delayed future earning potential ... you might not actually learn much more from an MBA.
5. If you are looking to stay in retail, then it is your own network, more than anything, that will help your job hunt and upward progression. Starting growing that network now and when you come out with an MBA, people will notice. I completely agree with DaFonz when he says that you need a vision of your career path and how an MBA is a necessary fit. "Start with the end in sight" and that should be extra motivation.
6. Start with the GMAT. You've probably correctly identified your biggest weakness - that programs can't tell whether you have the smarts to keep up. For most people, a week isn't enough. In your case especially, the GMAT may be the make-or-break factor (which usually isn't true for those with an undergrad degree), so you'll need to give it your best. When you're looking at $50,000+ for an MBA, spending $1-2,000 on a prep course and some time on this is pretty small in the grand scheme of things. Whether that's 2 months or 18, only you can tell. You should be able to tell after a few weeks of study but you're probably being realistic with your estimates, which is a good start.
Not sure how (or why) DaFonz managed 15 seconds a question on that test when they give you closer to 2 minutes, but I'd suggest most people not follow his lead, to be safe.
Anyhow, I had more to say than I initially had thought. If anything, you can see that there are some very divergent opinions on what an MBA program values *from* you and what value it delivers *to* you. All you can do is do a ton of research and thinking about what makes sense in your particular situation prior to making one of the biggest purchases of your life. Good luck.