I think you’re forgetting how expensive international airfare was even in the 1980s. Traveling around the world multiple times in the 1960s, 70s, and 80s would have been very expensive compared to today (note: I’m considering airfare only, not accommodations)
Most people tend to think of themselves as "middle-class". Your family may have been. Or maybe that's what you grew up with and was normal in your community but not "middle-class".
That point aside, the 1980's was the beginning of cheaper travel. In the 1950's it was the modern equivalent of $45,000 (all 'modern' prices are pre-COVID inflation adjusted Perth-to-London). It decreased by by 82% by 1980. It pretty much leveled out in the mid-1980's to today, inflation adjusted. Although the same rates your parents paid probably would have gotten them business class tickets now.
Cloves have been found at Syrian 4th millennium B.C. sites, Tel Mozan I think, indicating an unbroken route to Indonesia. Our ancestors were not unsophisticated.
Looking at the options now, 200 eur is very doable, although there will be extra fees for luggage. But there have been almost 20 years in between! In 2004, 700 eur must have been around the average net monthly salary in CZ; now, the average net salary is almost twice as high.
So, from a purchasing power point of view, costs of flying have gone down about 7x for a Czech person, in mere 19 years.