The first digit of this style serial number indicates the last digit of the year it was manufactured. For example, this Les Pauls serial number is 7_6227 so it was made in 1957. This is how to date a Gibson Les Paul from the 1950s.

How do I date my Gibson guitar?

There should be a space after the 1st digit with the 4 and 5 digit serial numbers, and no space with the 6 digit numbers. The 1st digit indicates the year of manufacture for the 4 & 5 digit serial numbers, these were used from 1989-1999.

Why are Les Pauls so expensive?

The main reason why Gibson guitars are expensive is that they are made in the USA. All their three factories are located in cities where the workers have relativity high wages. As the result, the guitars must be sold at a higher price.