English is not my first language, so i hope i correctly understand what you are meaning.
I know, the site earning is based on views, but who wants to visit a site where there are some good (and in certain cases very good, like yours...) contents lost in a sea of bad ones?
Even advertisers, i guess, are not very attracted by this situation, and infact user earnings are every month lower and lower.
Paying for downloads, imho, could eliminate the spammers (no downloads -> no earning -> no motivation to post low quality contents) and increase the site appealing.
For art and video contents, which cannot be downloaded, should be sufficient to show a resized preview (for images) or a single frame (for videos), and give the user the possibility to view the entire content, which should count as a download.