Is he using the PC for work--if so then can his work pay for any charges accrued. Then you needn't worry so much about incurring the costs on your trip.
My hubby has to use a computer to fill out his time card for work..so when he is on a business trip--whatever the fee is for him to dial up and do so would be a reimbursable expense. And then once he is only--if he wants to do personal business on-line, then it is already paid (assuming that there is just a per connection charge and not a per minute charge).
Wilderness Lodge we were just charged 75 cents for the local dial-up connection. But it wasn't a business trip, so it came out of our pocket.