I fell into status but then liked it and became accustomed to it that I made a point of keeping it. I couldn't say how much extra I have spent, but over the years it's probably quite a lot. What I don't do is chase status for the sake of it- in other words the flights I take are for a reason (work, leisure) not solely to achieve or maintain status and I am fortunate that my travel patterns allow me to maintain status.

Silver is (IMO) relatvely easy to achieve and worth going for if you travel frequenlty, because lounge access and fast track are significant perks- but what it is worth spending on that is a pretty subjective question.