First, I want to make sure you realize that only InnerSpace is required for the
ismods software, which is all a lot of players use for gaming (whether it be EQ2 or other games.) InnerSpace+ISXEQ2 is also all that a lot of players will use playing EQ2 as well: There are free/open-source scripts for ISXEQ2 (i.e.,
EQ2Bot) that do allow you to do most things that you'd ever want to do whether it be controlling groups, crafting, etc. InnerSpace+ISXEQ2+isxOgre is the "premium" setup. The isxOgre package provides you with an elite platform to take care of pretty much anything you could want. It's VERY nice and well worth it. So -- long story short, you can start with one and work your way up and see what you want.
(I also think that all of us will give you a refund if you find you don't like things.)
If $16 for a full month of entertainment seems too high, then you probably shouldn't be doing it. Just one dish and a drink at a reasonable restaurant nowadays is more than that -- so I think of it as very reasonable. (Or, if you think of it as one trip for a 2-hour movie nowadays is more than that if just just buy two tickets or one ticket/popcorn/drink.) BUT, if you have zero disposable income and never go out or do anything for entertainment, then you probably should wait until your financial situation is better.
I'm not preaching here to you, as I know you weren't complaining, I just thought I'd take this opportunity to talk on the subject. I know it's a bit of a sticker shock at the beginning, but you have to remember that it's three pieces of software by three individuals that all work a LOT to make it all happen. This is all very complex business and it takes a lot of time and tedious work to get it right.
On another topic entirely, I do plan to change my subscription system so that one subscription will allow you to use all of my extensions. That means that $12 for three months will cover ISXEQ2+ISXEVE+isxAion (and any others that come along.)