Always check shipping costs prior to entering your credit card information. Many online stores are not located in the United States.

Is there a physical store that you can call to ask questions to? Can you call them to check on your order?

Some companies are not located in the country from which you are purchasing, is your order inadvertently going through Customs?

Make sure the company you are purchasing from carries parts for the merchandise they sell. Do they service their product?

Are they selling you just refill cartridges? Bottles of E-liquid are much more cost effective.