Was looking at this GiffGaf deal for £139.99
Had a look on tesco mobile (which I am on anyway) and saw that i could upgrade to the G5 for £5.50/month (24 m contract) (HANDSET PRICE)
I realise that this isnt a deal for anyone midway through a contract. But if you are looking into a new contract and this phone, this could be the way to go. Been with tesco mobile for years and highly recommend it.
I personally went for the 2GB option, for £16.50 a month (5.50 + 11)
The minimum you can do is £14.50 a month (5.50 + 9) for 500mb/month but this isn't as good value for money
which ever data option you go for, the handset part always works out at £132 over 24 months (0% APR)
hope this helps