Do you know India had nearly 550 princely states and nearly 250 of this states had their own Court Fee and Revenue stamps. Many of these states were too small in area and population, so such stamps were issued in very small quantity. And even major part from the issued stamps were either destroyed by government relative agency (ies) or found in damaged condition. So, available quantity is supposed to be a minor part of the stamps issued. If you are collecting post-independence, thematically or foreign stamps or say foreign currency notes or post independence notes or coins, this would be an endless collection because everyday new issues comes out and you have to keep on updating your collection regularly.
On the other hand, if you are collecting Indian native states fiscals, there is nothing new is going to be issued, thereby one can try and make a complete collection, and mind you these stamps were not for public use. All these states had issued few stamps and we are still lucky that we can get these stamps, though, as usual, most of the stock has gone to the UK and USA as there is a foundation which has invested huge money and collected Indian princely states' fiscals and have also published a standard catalogue specially on fiscals of Indian princely states (Koeppel & Manners)