I can't possibly imagine in America/Europe researchers having trouble paying the sub-wall fees. My university provides campus-wide access to 99% of the journals out there. My professor I worked for during the summer had stacks of research journals on his desk every day, all of which are not free.
As already pointed out, arxiv.org is probably your best bet for accessing journal articles. The exceptional papers on the arxiv end up in these high-end journals anyway (as far as I know, someone can correct me if im wrong). So you're basically getting a free-screening of the papers that might end up in Physical Review, or Nature, etc.