If you were trying to rank your money site using press releases, then you will need hq press release links and a whole lot of them to pass the link juice to your money site, in order to rank and bank.
Or if you were referring to ranking the press releases as your money site, you can in fact test the authority of the press release site by a simple test - if you have an account with those instant link indexing service, just submit the entire lot of press release links to that instant link indexing service, and continuously check the SERP for the keywords that you are targeting. Normally a powerful press release site would get indexed and ranked for that keyword within 8 hours and you may use that as your best bet in terms of site authority -- this can be a very good parasite.