It was nice surprise, when I come across this item on web auction, and for starting price of few cent, that in the end go for very affordable price for this material. Normally, I "jump on train" and go for it!
Simple, if You can not have some early material in Your "global" collection, try to have at least, one sample from each country, of each early period. And when You have it - try to have something exceptional, not so rare, but something that is worth investment.
Sample that I purchased (shown here) are "not so nice" quality, but if it will be in 'perfect" condition, I will be suspicious that it is fake!
Here we talk about Bosnia and Herzegovina, better say Austro-Hungaria, issue for Bosnia and Herzegovina (little bit history: Bosnia and Herzegovina, after that SERBIA "broke" Turkish Empire, was "avarded" to Austro-Hungaria, like compensation for war effort, and SERBIAN are left empty hands) that was made in 1900 yr.
It is second set in row (first set was in Kr [krone] face value, and second start with H [haler] face value), and difference between first and second are in face value number, that come up, and down (in second set). If we search around, this issue at complete set are not so expensive like ordinary human can think. first set in "basic" option can reach around 60.00 euro in used condition, and second set can go even less than 60.00 euro. because I didn't have wish to "run" after so many "option" in this sets, and keep it in my stock, I decided to obtain one like this shown in PROOF-Print option, that well satisfy any serious collection, and will have price stable in near and far future.
How much to prepare for one like this? Really all depend of timing, quality, specific catalog number - but between 50-500 $ will be need to have one "nice" sample!