Comparison still holds, because if you buy a cluster with X amount of RAM the price will be roughly the same as a single server with X amount of RAM. Except that for some large X there won't be any off the shelf servers you can buy with that amount of RAM (let's say 2000GB), but lets be honest here, 99% of companies needs are under that X especially if we're talking about startups.

You're assuming there are people competent of building such systems who are ignorant of the fact they can earn that money anywhere in the world.