Make your own. Tractor supply co has 1/2" or 3/8 rubber mat, cut to 7-8 ft. Pitching plate and spray paint. Also get rubberized adhesive and it will roll up and travel with you anywhere. Costs about $75.
We have the Club K Powerline Mat. While I would never pay $300 for it (I got it off of craigslist for $75 with a bucket of balls and a radar gun) it is a nice product. Have used it on a gym floor and our garage floor...no slipping.
I used the carpet runner for one Winter in the garage. The runner has no padding, and it was hard on her knee and hip. I don't have a Track Supply near by, so I order the brown pitching mat on Amazon ($129). She loves pitching on it because it not as hard as the concrete. It's a good mat at a reasonable price. The power line is important for my DD to know where she is stepping. I have even vacuumed it a couple times, and it looks brand new.
PB36108 3' x 9' Clay Softball Pitchers Pitching Mound Mat With Power Lane Pro, Amazon $129.