Social Networking Platfrom for hobbyists

Hi Guys!

I hope you all are having a great day. Listen, developers! I have got a wonderful app Idea for you guys. See I am a coin enthusiast, my brother likes to collect " Stamps" and I have got a friend who just loves to maintain an inventory of precious stones. Whenever, we find something new related with our hobbies, we share it through whats app. So, why cant we have a separate and dedicated social media network for hobbyists? the same can be maintained through an android app.

Features,

People can share the photos of their owned stuff
They can chat
They can put their valuables on auction
They can maintain a wish list
They can discuss their hobbies

I think we don’t have any such platform available for enthusiasts. Looking forward to hear from you guys, any inputs or other useful information in this regards? Please comment on the technical and financial aspect too. If we can end up with a sustainable social networking application?