If you buy a tank that's at the very least better than 2L and is DOT certified, than you won't have to spend the extra $130 for a filter either. If you have a handy friendly dive shop, just use them to start, it will save you from having to deal with a whole other aspect of the sport for a while. Most people don't have access to an easy way to fill, or they shoot a lot, so they get compressors, if you don't need to, don't.
If you really get into shooting a lot, I would also suggest, if you have a home with a garage, that you look into how much it costs in your area to rent a nitrogen tank. The prices vary greatly so you would need to run the numbers. This is really the absolute best option; no compressor, clean and dry gas, fast. They are big 6kpsi tanks, so you need to have easy access for tank swap outs. You will find that there are very many ways to do this stuff. It all depends on you, what you know, what you want to bother to learn, how much space do you have, how much are you willing to spend, how much time do you want it to take, where do you want to do your fills, is noise going to be a problem? The hardest part of getting into pcp airgunning is figuring out the answer to these questions to your own satisfaction. Once you get the air supply down, the guns start piling up!
