We get a lot of folks that tell us they have a collection of postcards with "Rare Stamps". Usually they're referring to stamps like these: These are usually common Washington–Franklin Issues , issued from 1908–1922, Benjamin Franklin 1902 series issued from 1902-1917 and US Regular Issues issued from 1922-1931. Most of these stamps were printed in quantities that reach into the billions, so they are definitely not rare by any account. Just because something is 100+ years old, doesn't make it valuable. Scarcity and collector demand make things valuable. "But I just Googled these stamps and they're selling for $50,000!" you say? Perhaps you see something like this: First, it's doubtful that any of those stamps have actually sold for that much. You need to look at SOLD prices [ebay.com] There may be a few of these there that sell for more than $1, but for used 1c stamps on postcards, usually it's because of the cancel or postmark,
I seem to get a lot of requests this time of year from wedding planners. Old postcards make great "Save the Date" cards for weddings. For smaller wedding you might be able to get away with sending original cards, but a more economical approach is to reproduce the cards or incorporate the images into a new design. Here's the end result of easy wedding invitation project. I offer high-resolution scans of most cards for a nominal fee, which can easily be incorporated into Save the Date cards, or any type of graphic design project. There are tons of print shops that will do low-volume postcard printing - VistaPrint, printsmadeeasy.com and postcards.com are a few - but not all do matte finish, which is usually better for that "vintage look". Some printers can do different paper stock which can emulate the original linen cards.