Blackberry contracts

[stamp]

I have an off line Blackberry 7100 unlocked and want to try it to see if it works for me.
Is there a deal giving me the required service I will need for free or almost.
I know the 12 month contracts are also to subsidise the phone. I have that so surely the tarrif will be nearly free. ( I don't think I can use a pay as you go tarrif on this? )
All really new to this, so laymans terms please.

[rich 36]

Would like to help although not sure on that model TBH

talktime contract needed as usual
but alongside that a contract for data runs as well

mines T mobile about £15 ea roughly

8700BB BTW

[stamp]

Anyone else?

[rich 36]

I use this lot of boffins