I have already decided what I want to purchase.But when I check out two items I cannot purchase why?

[cmcmedical]

I want to place an order for all the items in my cart but,when i proceed to check out.It says that I cannot purchase 2 items as the shipping cost is not specified.I contacted the sellers directly but still there is no reply.Please help as i need to place this order today.Thank you.

[pierrelebel]

What is the listing number of the item(s) you wish to purchase?

Is the seller located in the USA?

Does the seller ship to Canada? (not all sellers do)