UK restaurants — ur doing it wrong

Today's dinner, compared with expected price for same in the UK:

Item	US price	UK price
Ribs, rack, 3/4	$15.50	£13 ($26, at least)
Iced tea	$2	£2 ($4, if you can find it)
Iced tea (two refills)	$0	£4 ($8)
Slice of pie	$4.50	£4.50 ($9)
Tax	$1.30	£3.50 ($7; included in above prices)
Tip	$5 (20%)	£2.50 ($5; 10%)
Total	$28.30	£27 ($54)