If you feel like you love slabbed books then go for it??? I would suggest that if they're beater copies, or even VF copies to refrain from grading them if you're thinking of trying to flip them. Also, start you tubing grading examples of what a 9.4,9.6, and 9.8 look like. That way you have a better idea on grading and can make a better conclusion whether its worth slabbing these books to flip them if that's your goal.
Personally I only like to slab certain books that either mean something personal to me, have great covers, are scarce (like golden age books), or are something I can flip in order to reinvest in the comics I'm trying to upgrade or acquire in my collection.
I got a complete set of secret wars in great condition but I'd personally would rather have those raw. Some books are just better raw for me, sometimes it ain't the same when they're slabbed.