Cashback sites
Whenever I use these sites I always go there via one of the cashback sites such as Topcashback or Quidco.
Based on my experience the price you're quoted is the same but you get cash back.
For example on Topcashback a search on Confused.com pays you £2.30
Expedia pays you 11% on hotels, 3,5% on rail, 5.5% on car hire and 1% on flights.
There are lots of other shops and websites on there. For example Sainsburys online groceries gives you £3.03 as a new customer and £1.01 as an existing customer