Hungarian currency was 100 filler = 1 korona (Hungarian for "crown). Magyar Kir. Posta (Magyar Királyi) means Hungarian Royal Post.
Below is the 75f (Scott #120) with a good clear postmark, dated May 2, 1918, showing it was placed on an item mailed from the resort town of Balatonederics, on Lake Balaton, the largest lake in central Europe.
|Source: Wiki Commons; CC BY-SA 3.0. Attrib: W. Brandmayer|
The 1k (Scott #122) is shown below. This stamp appears to have a postmark dated November 12, 1918, one day after the armistice that ended World War One, with Hungary sustaining a catastrophic defeat.
The 1916-1918 stamps of Hungary are very common, for no more than a few dollars one could collect all of them. The value of stamps as collector's items has to do with rarity, not their intrinsic attractiveness or historical interest.