Hi: I see no reason to press. I once invested a hot press with almost super-human powers, but have learned that in a surprising number of cases there can be very little up-side, and definite potential for harm.
The whole hobby is getting so expensive these days; if forced to choose between the advice of Artboy99 and Krishoseign above (assuming the latter is being serious), I would take Artboy99's.
Here's my view: collecting is all about enjoyment, at least for me. If you enjoy slabbing as some do, then slab away. What I might caution you against, however, is adopting as your unconscious mantra "press and slab," as if the pressing and slabbing logically amounted to one choice, or a "single service." The matter can be confusing, especially when the party doing the grading is the same that offering to press. In my view, an ethical lapse unsurprising from CGC, especially when it was a monopoly.
But two different services are involved, and I'd try to bear that in mind, so you can choose wisely on the question.
Unless you have unlimited funds and the very idea of pressing somehow brings you joy, I would press only as necessary. And do my best to learn what that means. Enjoy yourself!!