Graphics tablet?

So, I’m looking at getting a Wacom Bamboo graphics tablet. The thing is, I’m having a hard time deciding whether to get the 4x5 or the 6x8. I am an unemployed student, so the price is a pretty considerable factor. I’ll mainly be using the tablet for digital art and some photo touching up/photo-chopping.

Would you guys say that the extra size is worth the higher price? Or would it be better to get the 4x5? I heard from someone that the 4x5 is actually better for doing art. Sometthing to do with not have to raise your hand to make strokes or something. What do you all think?

Thanks for reading,

~Cody