How high of stakes does HEM Small stakes go up to?
.25/.$50 No Limit, .50/$1 Limit and up to $22 buy-in tournaments
Pro version is $90. You can start with the small stakes version and upgrade later for $40, so you save $10 if you just start out with Pro. If the higher stakes are a long time coming for you, then maybe it's worth it to upgrade later, but I'd just spring for it now. Especially if you intend to buy the extra modules like Table Scanner and Leakbuster, which also come in small-stakes and unlimited stakes versions, with (I assume) the same sort of discount if you start out with the full versions.
In addition to Table Scanner and Leakbuster, they also have Omaha and Hold'em Vision Pro, an enhanced version of the Vision product included in HEM. And they just merged or bought out Table Ninja as well. I bought the Scanner and Leakbuster modules, and may buy the Vision Pro as well.
While I'm partial to HEM, either will greatly improve your game provided you use them properly. Their cost is but a tiny investment that could easily be recouped very quickly if you properly apply them.