To start this chapter -need really be "fine tuned" because too much politics are involved in this topic.
Because I'm not of this kind people, I will say what I mean, even if it will offend some one's feeling.
I will start with two illegal issue, in principle - same way that Kossovo start to issue own postage stamp. From start, little bit history:
Like everyone educated, know well, that Kossovo are/is/will be SERBIAN territory, and after Yugoslavian civil war, Kossovo start to fight, by terrorist way, for independence that resulted in bombing Serbia by USA, NATO, EU forces - not clear why, but it happen - probably too much money are involved (rumors about Ahtisari, Allbright, Clinton and other corporation).
Finishing this bombing with installation of UN Administration over Kossovo (UNMIK), which give (without any coordination with Serbian authority) "green light" to issue postage stamp with Kossovo inscription. Because Kossovo are not recognized by UPU, stamp are classified in UN-Kossovo.
Illegal issue like this Dinosaurs set, Princess Diana, Cat, Europa, Sportist, Pamella Parker, Nature and other topic, start to pop-up on market from 1997, 2000 and continue till today, Kossovo are most affordable for all kind of manipulators and "private" editors of this stamp, for simple reason, that NO any kind of order existed on this Autonomy - UN are unable, and in most cases corrupt to stop this illegal activity, and also more criminal activity in other sphere.
Where is printed this issue, who, how, no-one know, but it can be delivered like 50:50 if focused on nationality. Some issue can be "good" for Serbian part of Kossovo, and other for Muslim part (Albanian, better to define it). There where is topic like Monastery, Kossovo fight, Target - all this topic can be good for Serbian market, and there where is an topic Clinton, Charles, Diana - can go to Albanian market, we know why!
From beginning (year 2000 and 2001) face value are inscribed in DMark, and after it in Euros, and first set (officially issued) is from March 15, 2000 year, set of 5 value, face value of 4.00 DMark, and Michel number 1-5, topic "Historic - Archeology", printed in Austria and market value it around 8.00-10.00 euro.
Next issue come on November 12, 2001, with topic of "Children Painting", Michel numbered is 6-10, face value 4.00 DMark, but in dual nominal inscribed, also in Euro, no printer stated, and market value is around 26.00 euros.
Third issue come out on May 2, 2002 - same topic like previous, "Children Painting" and same design like previous, just face value are now in euros. Michel numbered it 11-15, and market will say around 10.00 euro per set. Again, printed not stated.
Quantity for this issue, more speculative types, imperforated, shifted perforation, color shifting - all this "errors" are available on market, but what is rare is really traveled mail from there.
In photos, You will find some samples of cover and post card delivered from Kosovska Mitrovica (Serbian part) and also from Kosovo but with Serbian postage attached!!!!! This few samples, will be worth investment, because rarity and because we see from it, that on Kossovo soil with UNMIK on spot, is possible to use also Serbian stamp, use SERBIAN post (like need to be - by way), and that UN Force are there just to protect criminal structure on this soil.
And here we come with some Scott catalog update - for this autonomy, I see that listing are for 2006 year, where have an issue 21 Sept. 2006 of International Peace Day (funny-tragicomedy for this issue), showing Rugova signing "peace" document with ALBANIAN flag behind(????? Albanian on Serbian territory - really "chutzpa"), Scott numbered it #58, valued on 7.50$, but I don't believe that You will find it less than 7.50 euro!
Next is Scott #59-62, set and s/s, of 4 value, Ancient coins that show some Roman Empire coin (again some illogical theme), same catalog value for s/s - 7.50 $, and for set it come to 3.75$.
and last what I see are for Sculpture issue in same 2006 year, Dec. 1, Scott number 63, and valued 7.50$.
Again - it will be hard to find it by this prices (in US$) - because on soil of Kossovo, today is valid (officially) Serbian Dinar, but Muslim there use just euro, when someone offer US$ they didn't react.