broadband costs
 

my broadband tariff is based on data volumes. With a p2p i can understand if I pay my provider for data I download but do I have to reckon with all the other data that my "peers" are uploading / downloading via my machine. Forgive me if this question is totally idiotic - i am a p2p novice

All trafic from and to your connection counts.
So when you use Limewire:
files you download,
files others download from you,
and the network traffic, it all counts.
When you function as a ultrapeer, there's more traffic than when you are in leaf mode

I have the same problem a 7500 Mb monthly limit :(