I would like to write about disadvantages of buying things through the Internet but I've got a problem with these words.

Probably the best word would be "delivery".
I have to pay for the delivery.

Would "sending" work in this context?
Prices are reasonable but you have to pay for sending.

I feel that there should be an object after "sending", so:

Prices are reasonable but you have to pay for sending items you ordered.

Does a reader understand that in this sentence I mean that a person who is to received something ordered online has to pay for sending items to him/her by a seller?

What about "shipment"?
Prices are reasonable but you have to pay for the shipment.