If you are a young driver, that has only driven inside your own country, and won most rallies in your class. Probably in a 2wd car.
Next year you would lile to try an international series. you are sitting down with parents or your team to plan for next season.

What is there to choose from:
Erc 3 jr, 2 wd
Erc 2 jr, 4 wd
Erc 1
Jwrc
Wrc 2/3

If this young driver would like to swap to 4wd, and you are going rent a seat in a good team.
The pricetag for a seat in a rally2 and a rally3 car should be very different, thinking of the teams cost of buying and maintaining the two cars.

For many youngsters that difference could be the same as yes or no to an international carreer in rally. Thats why rally3 has its place in the pyramidn. And it is all about budget, and what you are able to get sponsors to help you with.