I asked many questions like this before buying. I can understand your concerns. Some platform exports are not cheap. And I saw how friendly is the community here at forums and at their discord server.
I downloaded the trial version, followed a couple of beginner tutorials, and even if completely clueless, I got hooked by its' modern environment. I even did not let the trial period to expire. I bought my license sooner. Maybe you will be convinced and do the same, or completely dislike it and look for something else. And even if you are not quite sure if you like it and suits your needs after the trial period is over, then you could by a creator license (for win OR mac, NOT both), which will give you full access to GMS2 for a year. It costs about 40 bucks, not a big deal of money to risk. Then, when you know what to do, you could upgrade to developer license before your license expires and you will get with 30% discount.
The downside is, that targeting various platforms is going to be quite expensive, but worry not, 2-3 times per year, yoyogames offer discounts up to 20%-25%. With patience you could buy the licenses that you want at more affordable price. So far I have noticed that they sometimes (but not aways) offer discounts at Black Friday, December (Xmass), February (Lunar New Year Sale), April (Spring sales) and I thing I remember an August sale period. With a little research you can track the discounts history and plan accordingly... Watch often their blog, facebook and twitter...