What do you have in your collection now?

I agree with the point above, collecting is a hobby. Don't treat it as investment. If you invest, it's stock trading.

Collecting this thing mainly depends on your personal preference. I feel like you, the poster, have a wide range of interests,

jades, calligraphy and painting, antiques, and porcelain.

I will introduce you to a place, go and check it out.

You can go to Bobo Art Network to have a look. They basically have everything you like.