I agree with Jesta. You collect for the art first, investment reasons are the last. This is a difficult hobby indeed. To begin, I would suggest read a number of books on museum collections or auction catalogs from known auction houses such as Christie’s or bonhams. Some books on Chinese paintings and calligraphy also very helpful. As a beginner, I would not recommend buying from eBay, unless you have confidence with your knowledge and judgment about the authenticity of the piece. You can start from buying from reputable dealers or auction houses first.
to me, coins were stamped or casted in large quantities, they can not be compared with the sword fittings that are hand made and unique in every piece.