What are some things to be aware of that can lead to higher than expected total when making a purchase or checking out?

Taxes and mark-ups can result in a high overall total.

Two possible answers are:

Taxes and mark-ups.

Explanation:

Sales tax is added on to the total of a purchase. Depending on the area you're purchasing in, there can be both local and state sales tax. This will cause your total to be higher than just the cost of the goods.

Any prices that have been marked up will also lead to your total being higher than you expected.