First postage stamps of Iran were issued in 1868 and these stamps are known as the Bagheri stamps. These stamps were printed in Teheran in quantities varying from 3,000 to 8,000 in in four denominations, 1 Shahi violet; 2 Shais green. 4 Shais blue; and 8 Shais red.
This first issues were canceled only with pen marks and often you find covers with stamps which are not canceled. No postmarked covers have been found yet. These stamps are not expensive. You can get a good condition set for around $150 – $250. stamps with Watermarks could worth 4 times more.