I submitted 50 secondaries last year due to a low gpa and it was hell and expensive but it was worth it. I got bites from schools I never thought would be interested and I didn't get interviews from ones that I thought I would (Drexel, NYMC, etc...) You never know who is going to be interested and I'm ending up at a school that I thought was out of my league.
If you have the time to pound out the secondaries then go for it. You don't want to be a re-applicant. You can always turn down interviews once you are accepted somewhere (that's what I did at the end). You can also always withdraw and not do the secondary once it shows up.