$500 drones are low end. High end drones can cost in excess of $1 million. But this only defines the cheapest and most affordable hardware.

On the opposite end of the spectrum we have new technology like hypersonic cruise missiles which can cost $50 million.

Its more accurate to say the difficulty level of waging war has risen. Satellites can monitor a battlefield around the clock making actions like sneak attacks or flanking maneuvers more difficult. Its harder to take an opposing force by surprise.

Capturing territory is thus harder making a ground war more difficult in contrast to previous eras.

Today's battlefield is all about air power. Which is super expensive.