Tesco or Plusnet Sim only?

I have never used ebay or anything like that as I am not happy to put in my credit card details I know you can have a pay pal card which is much safer. I don't understand how you were able to buy the G5 phone for £120. It seems to be £129 + the £10 for a sim which I would not want. I am happy to stay with o2 if they are giving me a sim for what the o2 rep told me on the phone ie £6 for 500MB 500 mins and unlimited texts. This is better than I have currently and as good as anything else and more than meets my needs. Only point is I would prefer the grey phone to the blue that o2 have. It seems that the blue is exclusive to them.
I am not worried about the phone being locked as long as I can get this deal from o2. It is just that I don't understand who my phone is locked to if not to o2. Is there are chance that the phone is unlocked? Took the deal from CPW and I must say that the manager in the store was so helpful to me. I was in and out 2-3 times and Adam was most helpful. At a later date I went in to ask if they could help me moving photos to my SD card. I have not found the staff in the local o2 shop particularly helpful. Thanks again
Sue

I am elderly and whilst I do a lot of shopping online including my grocery shopping
I am reluctant to use a company I am not familiar with and yes I am a bit risk adverse
About 3-4:weeks ago.my Daughters Pay Pal account was used fraudulently
She received an email confirming the purchase It was for some archery equipment and was being sent to Russia The payment was refunded so no.harm done.
Whilst we are all happy to save money I personally would rather be safe than sorry. Thank you for your information and I do appreciate it
Sue

Bit rude !

Have always been with o2 and had no.problem with reception etc They have offered me a sim only deal for £6 which more than meets my needs
This can't happen until 23rd September which is fine
Thank you Sue