Sorry, but I am really confused. The way I have been reading the previous posts on here for some time, is that if go via AMS for example it is a lot cheaper due to the offers and also not having to pay the UK flight taxes.
Are you saying, I book one ticket, that is for example,
LHR -AMS – LHR -MIA – LHR – AMS – LHR
Do you then only get caught for the higher UK price on the LHR AMS LHR bit and not on the MIA bit.