betchecker.betfair.com/

Utterly hilarious how they keep claiming "to cut out the middle man" when in fact they do exactly the opposite

was just going to ask the same

As a Betfair punter, you enjoy greater value when betting with us because you cut out the middleman.

Now there is a way of checking the value of your bets – both those you are about to place, and those you have had previously.
Betchecker is a new website which allows users to compare winnings on Betfair with those of a number of well-known bookmakers. The prices are checked several times every hour and will display a comparison of how much someone placing £10 on a particular bet will win on an upcoming event, or would have won on something that has already taken place.
Betfair is confident that we offer the best odds – but even if we don’t on every single market, Betchecker will hopefully show that over time, the best value is with Betfair.
Unlike current odds comparison sites you may have used, Betchecker can ‘remember’ who had the edge over the last day, week, month or longer.And to make the fairest possible comparison, Betfair's potential/actual winnings are always displayed less the maximum 5% commission.

The best way to learn more about the true value Betfair offers its customers is to go and play with the site for yourself.

https://betchecker.betfair.com/