To have chosen and area and a weapon type to collect, is not always easy, but when it is done the hard work start.
I have collected Indian swords and daggers for 40+ years, and have come to the conclusion, that especially in the first years of collection, books on the subject, and other bordering subjects, architecture and such are as important as collecting itself. Or maybe I should say, buy a handful of books, visit as many museums, and private collections as possible before you start buying any weapons.
Afghan shamshir blades are so much like Persian and Indian ones, that I doubt if many if any collectors, in most cases can see the difference. The Afghans also made a lot of other blade types besides the shamshir blades, and they exported these blades to Deccan and other places likely along the Silk Road, so it is a very big area you have chosen.
You should also be aware that sometimes the blades are older than the hilt; if decorated, they may be decorated at the time the blade was made, or maybe later, but it can also happen that the hilt is older than the blade, especially on Indian swords.
Happy hunting
