Different between the Pathfinder/deluxe/guest artist edition and hero pack

[Sigma88]

I'm a huge fan of Pathfinder Adventures and I only just found out that these 2 exists.

Now I am about to buy one of these but can anyone tell me what exactly are the differences between the 3 (standard, deluxe, guest artist). The guest artist seems to be the cheapest and bigger bang for your buck as you get extras (and a bigger box :) ) along with it. But the deluxe is more costly. Is the guest artist edition really not all that interesting to be priced at the same cost as the deluxe version? Anyway, what else you can anyone tell me about these two and your opinion on it?

I'm very intrigued about the hero pack, the one where you get allies individually. But my question is are these allies in the core set already? Or do I have to buy them separatedly?

Thanks!