Dunno about a re-test fee, but another guy I met there was one his second class 1, he had one 12 months before but was doing quite an intense atpl(a) course, ME IR etc... only about my age, early 20's.
Well he went in with a class 1, and came out with a class 1 however he went in not wearing glasses but came out needing them after his second test.
I went in for my eye test and had 20/20 vision, i.e perfect, a year into it all I found I couldnt read teletex etc on tv with out squiting big time, I now have glasses for flying and driving, I don't need them legally as I can squint a little to read enough of the letters the class1 requires, but it just shows things do change, i'm only 1 prescription above minimum, but they said if i'm still studying from screens and books close up i.e (frigging cpl(h) groundschool) I may have to keep an eye on them until I stop all the reading crap as I could go up another prescription.....
Get your class 1 done before spending a penny K. Also, not to do with flying, my friend tried for the army to find he had the slightest heart murmer, he was 18, never had a problem with it, and doc's say more than likely never will..... just saying that for instance would stop you obtaining a medical and perhaps never cause a problem your whole life, and he had no idea it was there.....