I'd wait a bit.
Your GM-30 can be programmed to receive frequencies outside the GMRS band, so as you learn, you can try programming some local amateur radio frequencies into the radio you already own. That'll let you listen in and start learning some of the procedures and habits of local amateurs.
I often see new hams blowing their budget on their first radio, without really having a good idea of what they need. I know your budget is tight so don't rush into a purchase just yet. As you learn the subject material and listen in on local hams, you'll get a much better idea of what you need and what you want. You may find that the local 70cm band is dead, or that most use a digital mode. You may find that 2 meters is where the local action is at, and you can choose a single band radio to fit your needs. You can also talk to the local hams at the club, and you may find, as suggested above, that there are used radios for sale.
Don't be in a rush to spend money. You've gone back and forth on whether amateur radio is right for you a few times. If budget is a concern, wait, there's no rush. With Amazon, you can find an inexpensive radio and have it delivered quickly once you have a better idea of what you need.
