I think this is a great deal for those who want a pretty good contract but are skeptical about sending in cashback claims (which seem to be getting rarer by the day anyway).
e2save are offering the following:
Nokia 6300 Xbox 360 Arcade £150 auto-cashback for £35 per month on a 12 month contract
02 400mins 500 texts
So after auto-cashback, it works out as £270 for the term (£220 with quidco), an average of £22.50/pm (£18.33/pm after quidco).
So given that an Xbox 360 arcade is around £120 and the phone is about £50, you're paying £100 or less for the actual contract.