#6067 vintage fancy car brooch.  
We talked about the cyclical nature of most commodities while good quality antique jewelry has steadily gone up in price. 
But, what are these values? What are we talking about?

In fact, there are a lot of ways of seeing value in a single item. 
We might be talking about wholesale; retail - retail bricks and mortar store; retail online; retail other online (not to mention names); auctions; insurance; resale.  Each one of these is utterly different to the others. 
When you buy from a famous store or auction house, you will pay a lot more than you will pay from a small dealer online; what you insure the jewel for is yet another matter. 
Just to set the record straight: most appraisals that involve monetary value (as opposed to purely gemological information), are for insurance purposes. 

#7182 Giardinetto ring.  

Finally, remember that when it comes to selling your item, you might not immediately get what you expected. Perhaps you did not buy the best item available. Perhaps the timing is not good for that piece in that forum. Take expenses into account. It might take a while, but all things being equal, if you bought a good piece of antique jewelry, chances are better than good that it went up in price. 

I hope you will not sell your jewelry. Keep it for your daughters, grand-daughters or great-nieces. There is nothing like a piece of jewelry handed down in a family and providing a concrete link between generations.

#5293 Flower brooch.