This is what giffgaff offer on a bags that have allowances >> https://giffgaff.com/sim-only-plans
When want to top up credit >> https://giffgaff.com/top-up
Giffgaff offer mobiles as well can buy new/refurbished >> https://giffgaff.com/mobile-phones
Pre-owned mobiles >> https://giffgaff.com/mobile-phones/pre-owned
Can earn payback as well if want to get involved that can turn in to cash/credit to account or use on charity >> https://giffgaff.com/index/payback
It's like Texaco star scheme that once was which mean you paid more in the long run, also like Credit Card reward schemes. Wouldn't you rather have more money in your pocket? I used to be on £10 goody bag and giffgaff notified me I was paying too much and advised I drop to the £7.50 goody bag. How many other mobile networks offer that?!