Differing Shipping Costs give to Buyer than Actual Cost of Label

[tjjthome]

A Buyer bought an item listed using the USPS First Class Standard Shipping offered.

They were given the cost of and paid the cost of $2.46.

When I printed the label, it cost me $4.44.

I've had this happen several times before, but decided not to question it.

But I would like to understand what is happening and what I can do differently so I don't keep losing money.

On higher priced items, it's not that big of a deal.  However, this particular item was listed and sold for only $2.99.  That $1.98 discrepancy between the paid shipping cost and the actual shipping cost makes having sold the item a bad deal for me.

Any answers will be appreciated. Thank you.

[kensgiftshop]

Check and make sure the listing is set up for First Class package and not envelope or flat.

[tjjthome]

Thank you for replying.

It doesn't give me an option to choose package vs. flat.

I put in weight and dimensions.

Now that it's sold, I can't go in and view shipping other than it says Standard Shipping USPS First Class.

I must be missing something.

[tjjthome]

The cost range it gave me when I listed it under USPS Standard First Class was $5.40 - $5.85.

I don't understand how it let the Buyer buy it and quote them $2.46 shipping.

It was a 6 oz. package (bubble mailer, although that info was not required to list)  with package dimensions of 9" X 6" X 2".

It didn't ask flat or package.