Great to read all these familiar recollections. It's funny how these prices from our youth stick in our minds, but not those of later decades. I can tell you what a Mivvi cost in 1959 (6d), or a half of cider in 1968 (10d); I know that a Mivvi or similar lolly would now cost about £1, and a half of cider about £1.60 but I wouldn't have a clue what either of these cost in, say, 1980 or 1995. The only fixed points for me in later decades are what we paid for houses or cars, and (sometimes) what our salaries were.
I do remember what I paid for certain items of clothing over the years, and am astonished at how (relatively) expensive they were. I treated myself to a very pretty T-shirt in about 1990, for £10; today I wouldn't pay much more for a fancy t-shirt and could probably get it for less.