Best example is DASH, for DASH you need 1000 coins = 83.000 US$.
See why I keep saying that 25M ESP for a masternode is not enough?
At this point, $83.000 of ESP would be 1.9 BILLION. Per masternode. Of course this is not comparable, but you get the point. It doesn't have to be "affordable" for the average Joe.
The fact that MN coul be currently affordable for the average Joe is due to the fact that ESP is still comparatively cheap and not due to the fact that 25 mil are too little, i mean, we are currently on page 3 of coinmarketcap!
If we imagine that 10% of the current 20 Bil ESP supply might be lost / forgotten / locked on exchanges (realistically credible since it's a 1+year coin and i'm not even sure how the swap is being counted here)
That whould give us 18 bil / 25 mil = 720 MN MAX. Which is the unbelivable scenario in which 100% of the aviable supply is neatly stacked and organized in 25 mil MNs.
Even 50% of the total supply locked in MN seems optimistic to me, so i think we could get around 200 MN active max with 25 mil masternodes (and i'm still being optimistic). Really not too many.
MNs have value because the underlying currency has, not because you need to buy 10% of the total supply to set up one