Use JPGs if you don't need the transparency, they are smaller. A campaign remains until you erase it. 3 gigs is a lot of JPGs, sound files will kill you, recycle when not in use. As for buying a subscription. Dynamic Lighting really adds to the visual flavor, Transmogrifier saves a lot of time, and the API is worth the price of admission alone, if you learn to use it and if you want to put in the effort. Learning to use all of that is an effort, probably equal to a College course with math. For casual use the platform performs adequately, like a subway system. For a few bucks you can step up to a banger car, it will get you around, a few more sheckles and you get an adequate vehicle that, with effort, you can turn into a race car. Getting off the bus will require you to learn to drive...