Being a fairly new collector of paperweights I have learned a few lessons which may bear mentioning.
1- Buy good paperweight books and study well.
Older books may be less accurate as new information comes to light.
2- Quality over quantity!
Dull weights from a famous maker may make for dull prices.
A chipped or damaged paperweight may be good for study but usually not so good for investment.
There are exceptions of course, a $20 Clichy with scratches and a small chip to the base would be a good buy.
Cracked weights have little investment value.
A big batch of cheap weights may seem like a good buy, but if you plan on selling them online remember
shipping and packaging costs (for you and the buyer).
I have found that Chinese copies and Murano pieces are often thrown into a lot with a good weight,
so if you want samples of those styles you may very well get them when buying good weights.
3- Watch eBay auctions, even if you have no intention of buying the prices achieved will give an indication
of the lower end of the market. As a bonus you may learn to identify some makers, you will see labelled weights,
see lots of Chinese and Muranese weights and learn to recognize their styles etc.
If you find a weight interesting look it up in books and online.
3a- Do not trust an attribution given on eBay unless it's from a reputable dealer and accompanied by
evidence, ie signatures (that you recognize), signature canes (that you recognize) etc.
Beware that Baccarat etchmarks can be found regularly on Murano weights.
Sellers may not be trying to cheat, they may simply be mis- or uninformed.
3b- Learn the copies. A few makers have made more or less successful attempts at copying well known makers,
the best I've seen are the copies of a New England nosegay on latticino ground.
There are many fake signatures, signature canes and signature etchings - learn to recognize the more common.
In particular the common Baccarat and Schneider etchmarks; and the well documented false Paul Ysart "Dropped Y - PY" cane.
4- Watch brick & mortar auction house's websites for their listings. Many b&m's post online auction catalogues
along with prices realised.
5- Values give in books are usually higher than what is achievable, increasingly so with older books.
6- Antique French usually perform well, with scrambles and Baccarat pansies being in the lower pricerange.
7- Don't spend big bucks on speculation type items, an unclear auction image may be hiding a jewel but it may
also be hiding a dull tourist piece / copy
8- Check a seller's shipping policy and price when buying online.
Some sellers charge exhorbitant amounts for shipping and handling.
9- When buying to sell take into account all costs, there are obvious ones and hidden ones;
auction fees, auction premiums, picture fees, shipping, packaging, PayPal/Bank/Creditcard fees, time spent etc.
Remember that brick & mortar auction houses also charge the buyer a premium, so if a paperweight has a fair value at $1000
a buyer may only be willing to bid $850 to offset the 10 to 20% usual premium.
I'm sure there's lots more but this post is getting long
