Personally I myself have no qualms about sharing how much I pay for my fish, though I whole heartedly respect those that do mind sharing. I don't question the why of people's actions often though. It's like trying to understand why my girl friend love's collecting Coach an Louis Vuitton bags. I truly don't get it, but respect it. She can try a hundred ways to explain the appeal of them and it will just go over my head. It's the same for her, she'll never understand the vulgar amounts of money I spend on my fish and snakes. Still she respects me, sometimes with her draw dropped and clutching her chest though. lol. So though it is an interesting question, if your anything like me you'll find the answers to your question unfullfilling. Mostly because you can understand all the reason's why someone wouldn't, but just don't feel the same way. Still I could be wrong, maybe your more empathetic than I.