Why is tomato paste so cheap?
What you are observing is that the bulk of the price of tomato products is not the tomatoes.

The price of the can and shipping far outweigh the few cents of tomatoes the can contains.

With fresh tomatoes you are still mostly not paying for tomatoes. You are paying for the gas and people to ship and stock your tomato and all the other tomatoes that were shipped with yours and thrown away damaged or unsold.