I was trying to get back into Graphic design and thought maybe I could use GIMP. It's not like PS is the only thing that works.

Nope. GIMP works against you. There is not native support for so many things that you use every day in PS. Brush dynamics are just really bad (it looks like if I had a tablet I could do something), the interface works against you, being in the way and shit.

Is there a package of plugins/addons that I could add all in one go that make GIMP a viable alternative to PS?

It seems like it would be easier to save the money up for PS rather than work to make GIMP usable.

nearly certain cs2 is free.

To be honest, a lot of it has to do with whatever program you have learned/know how to use. Gimp is very powerful. No, it is not as powerful as Photoshop, but it certainly is capable of doing 80-90% of what Photoshop is able to do.

You could checkout Gimpshop, which is a older version of gimp, made to work like photoshop, but it is not as powerful as gimp.

This. Free from Adobe.