Just ordered my baby a kids fire tablet. In installments though cause this mama ain't going broke this month lol. I got…

Just ordered my baby a kids fire tablet. In installments though cause this mama ain't going broke this month lol. I got the amazon prime free trial. So instead of 99.99 plus shipping it's going to be 80 something and free shipping and only will charge my card $20. Can I cancel that membership once I receive the tablet and still get my order for 80 total or will it go back to the 99 dollar fee??? I never tried prime trial so I'm clueless. But definitely don't order things enough on there to actually keep the membership.