How much does it cost roughly to patent/trademark a product for the whole world?

(uming you are in the UK......) initial application to UK intellectual Property office is free and subsequent costs are �200 to process it. That's if you do it yourself which is a bad idea because its a legal doent and needs to hold water if challenged later. Patent attorneys charge �500 to �3000 to do if for you. The other person's answer of �10,000 is about right I would say for subsequent international patenting although you could spend up to �20,000. Never do that unless you have some kind of realistic commercial deal in place. I know people who have spenmd �30,000+ on patents without earning a penny.