Tacoma Mechanic help

So lately I have noticed that my 06 Tacoma has a slight shake to it when above 50 mph. It's not a really bad shake. I'm thinking it could be the shocks because it dolphins a little so the bumps in the road might be causing the shaking. Doesn't feel as solid as normal driving around bends or again at high speeds. I have no problem with buying new shocks to upgrade but I want to make sure that is the problem before I do. I'm a poor college student and the dealer is asking to much to just look at it the stupid thing . I was wondering if there is anyone here in az that knows a lot about Tacomas or trucks in general or knows someone that could accurately diagnose this for me at a low cost. It would be greatly appreciated.
Thanks

 

When was your last wheel balancing?

 

4 or 5 months I think

 

The shocks would be the last thing to look at, as it really doesn't have much of an effect on something like this.

First things...

1) Get under the truck and do a visual inspection for worn bushings, shake stuff around with your hand for anything that's grossly torn up
2) Jack up one side of the truck, shake the tire around and see if anything feels loose (like the wheel bearings for example).
3) Wheel balancing. Get them to do a road force balance.