Not that I'm an expert, but I'm pretty sure you are. Maybe you took a few pre-recs over the summer, but I'm still not sure that's as much of a weak point as you think it is. Let me explain this quantitatively:
In comparing you to med school matriculants from 2011:
Your sGPA is in the 37th percentile. Your cGPA is in the 29th percentile.
That's certainly not amazing, but thats decent. Keep in mind this is matriculants, not applicants.
Your mcat is in the 11th percentile. And your verbal (which med schools seem to think is correlated to your step 1 scores) is in the 15th percentile.
Not trying to be mean, just showing you where you are relative to last years matriculants.
Let me put it another way. I've been talking to adcoms about what kind of person they want and would get the most out of it. What I've heard is that the people who need/benefit most from these programs are those with medium to high mcat, good ECs and LORs, and have done very well in recent science class, but continue to have poor numbers because of previous work. I don't think you fit into this type based on what you've said. Your gpa is decent, but your mcat is low. If you try to keep polishing your strengths without addressing your weaknesses, med schools will notice. If after you take the mcat (may, june, whenever) and you want to keep taking classes on the side to boost your gpa, thats certainly not a bad idea. But 50k is a LOT of money, and unless youre super rich, I'm not sure you wanna spend that on something that isn't necessary. Additionally, you have to basically destroy your SMP classes to get into med school. Anything lower that a 3.5 is (usually but not always) not a good sign. If you do really poorly, you lose your money, time, and any remaining shot at medschool you had. So unless you NEED an smp, I wouldn't recommend it. They're not "have fun during your year off" programs, they're boot-camp kind of programs.
Anyway, the point is, I'm pretty confident taking the mcat agin would be infinitely more beneficial than doing an smp. Plus, pretty sure you need at least a 30 to have a shot at US MD schools...