Not my direct experience, but my son bought a ring for his girlfriend that looked perfectly glorious online and very tacky in material form. He returned it and went to a local jewelry store.
I bought a veil on ebay that didn’t compare in any way to the texture of those I found at my local David’s Bridal or the fabrics in fabric stores. I did order some gorgeous faux jewelry on ebay that will be used to accent the veil I make myself from the fabric store.