Definitely gotta agree with Own. Though I think I have asked myself for this in the past, it makes sense why they did it. Also, if you don't have any skills with 5 silver points yet, then you'll just have gold saved up for when you get 5 silver. Then, you suddenly have a skill that just got 2-6 points put into it all at once. I never really thought of upgrading skills by 1 point as a massive increase that I need to get immediately. So yeah, I think it should stay as is.