The Studio will accept any dies with the appropriate adaptor or shim. So you can use Go! or Sizzix dies in the Studio. They are different thicknesses so need different adaptors.
I use the generic dies a lot: squares, triangles & strips. In addition, I have the winding ways die. Pricey, but
I cannot imagine doing a quilt with curved pieces that were not die cut. If you are only going to use a die for one quilt, you have to consider the price.
The price you quote is a good one. How valuable is improved time and accuracy for you? Take a look at the Accuquilt site and factor in the price of the dies you'd like before you make a final decision. Accuquilt had periodic sales on both GO and Studio dies, so you can purchase a couple of must haves, then add to your collection as they go on sale.