Hey, calm down! I can't keep up with all these postings...
Shirt, tie and epaulettes - leave at home. . .The rest, you'll need, sooner or later.
. .PPL Medical: cost varies depending where you live and which Doctor you visit. Anything between £50 (no ECG required) and £180 (London area and with ECG).
The CAA website has a list of AMEs (Flying Doctors) - pick the ones near you, and ask them how much.
Medical content - pretty thorough, to confirm that you aren't likely to pass our or worse while flying, and can see and hear adequately. There are illnesses that will prevent you flying as pilot in command - things like diabetes, epilepsy, anything that affects your consciousness, heart problems...