So what's the best way to spend AP? I've heard of Eden Crystals, but I ain't the gambler type. Can anyone suggest any alternative way to spend AP and earn fairly from it?

Let's start with around 5k-8k AP.

Get backpack expansions ...seriously... the game is frustrating...lots of stuff cant be stacked ...and u start with lil storage capacity.

First, best is to spend it in weekends when there is a tiered spender that gives a nice bonus on top of what you're already buying.

If you want to use it for yourself backpack stuff is nice yeah. If you want to sell the items eden crystals, safety stones, memory tomes (atleast in sapphire) are a good way to get gold.

Actually, a lot of people make money in-game by selling Eden Crystals to others rather than using them. Right now, ECs are the most expensive they've ever been, you can get up to 90g each for them on Sapphire. And they're pretty much always in demand.

I know a few people who wait until there's a tiered spender, buy stuff like ECs or anything they particularly need from the Item Mall, then get the costume pieces from the tier and sell those. Though you usually need a high amount of AP to get anything good from the tier.

As an aside, I agree with Rockman - backpack space is a nightmare in this game xD

im thinking of using them for thermal packages. MUWAHAHA >

Sure, get a few of em...
It depends on what your goal is...

Do you want to make some money teh safe way? -> Get ECs and sell em.
Do you want to make some money if u get lucky? -> Get Thermal boxes or similar things.
Do you want to have a nice start into the game and avoid frustration? -> Get some backpacks x(