Hey CJones,
As 2earls indicates there are sites that will give you prices for prescription meds, even some that do price comparison and price guarantee. You do of course need a legitimate prescription to be in a position to benefit. Other sites dispensing bone fide meds for diagnosed conditions have their own GP who will issue a private prescription but again you would need to show how your condition was diagnosed and perhaps send copy documents to confirm the diagnosis. These are regulated organisations and the range of conditions they are permitted to treat is restricted; restrictions differ from country to country.
As for buying without a prescription, it is exactly as 2earls says but there is lots of information on this forum, if you invest the time necessary to read carefully you might just find what you are looking for, at least in terms of trusted suppliers even if prices aren't stated overtly. Vendors with a good reputation won't want to rob you, transactions are two way and they need their customers as much as their customers need them, if that makes sense!
Good luck with your research.