Output filter for hand pump

I'm getting ready to purchase my first pcp airgun, hatsan flash .25 caliber. I've decided that I'll be refilling with one of those cheap hand pumps found on ebay. After doing lots of research regarding filters, I still cannot make up my mind for which type of output filter will be sufficient for removing moisture. I've heard so many different opinions. I've been looking at 2 diffeent types of filters, cotton and desiccant/carbon/ect.

I'm wondering if the simple cotton ones would be sufficient for only $15-20? The ones with dessicant seem to start at $100. Would like to go cheap if possible, especially the fact my gun is only $285.I live in Ca on the coast where the humidity is somewhat low (around 50%).