As TranceJeremy correctly said, the use of ‘ye’ for ‘the’ is a modern mispronunciation. In any case, I recall it only goes back to the days of the printing press. There were several symbols used for printing, one which looked a lot like a Y (but wasn’t), was used instead of ‘th’ to represent the ‘th’ sound as one symbol (not a bad idea, actually).
So if you want to pronounce ‘Ye olde toye shoppe’ correctly, you should say ‘the old toy shop,’ boring, but true.
Oh, and anyone who begins a sentence ‘prithee sirrah,’ in a rpg is a complete Berkshire hunt.