I am a philatelist. Just a small hobby not professional.
I collect railway stamps mainly and also anything which catches my fancy. The foreign ones I bought from a professional collector during last year's Philately exhibition in Bengaluru.
-
You too can contact local philatelist and buy or go to Pune GPO and see if anything is available. Usually they keep that year's only....
more... Professional's will have old ones.
-
The most in-demand railway stamp is the "150 years of IR - 2002", I have posted below.