I really dislike this approach. Finding the free version is harder and the links are much less likely to be permanent. I've found a huge amount of data, code an

I really dislike this approach. Finding the free version is harder and the links are much less likely to be permanent. I've found a huge amount of data, code and extra material is simply missing now. In 20 years are you confident someone will maintain the same url and content? Can you afford the open access option with the journals you want to submit to?