Hi Kyle D,
it might sound strange, but for me your free set looks more interesting, then the paid pack - I can't tell you if something will sell or not, but the pack you offer for sale doesn't look to appealing for me - for me to look more appealing I would try to build a larger island where everything looks nice together... with some bridges as well and also quite important- that there are some bordertiles to let some type of terain go over a different type of terain. What kind of game are you aiming it? If it is something like heros of might an magic if would focus on this.
I would also try to improve the looks of the trees, they look a bit blunt now (just like green blobs) would you feel confident enough to add maybesome branches?
Why are there gaps in the middle of the gras tiles?
(Me personal I would like to have a larger variety of different tiles beforeI would buy)
Whish you the best ... as said this is just my personal opinion - so take what you find helpful and ignore the rest :)
the frog