This is a case of "You get what you pay for." The cheap cutting mats are not the best for your cutter. Since you are going to be using your cutting equipment a lot, it's wise to invest (yes, this is an investment) in the best equipment. The best mats to purchase are either the Fiskars 24" x 36" - you can get it at WalMart for under $30.00, ot the Ofla or Omnigrid green mats. They are more expensive, but I would assume you could get them at Joannes with a coupon to make the cost less.
I have the original Fiskars grey with orange mat. Have had it for nearly 15 years. I do a lot of cutting. The mat is still going just fine. I'd like to get the yellow one, but keep resisting as there's nothing wrong with my grey one. It's just that my favorite color is yellow!
Now, there have been cases of a blade being duller than it should be from the get-go. I have been using the Harbor Freight blades & am loving them! The current blade is 4 months old! Probably ought to think about changing it out, but it' still cutting just fine.
Good luck.