If 350-400$ was a low price back then what do you believe they consider 250 nowadays?
A lesson?

Yes, I'm sure millionaires that have probably been mining since the double digits days are quite bothered by a price drop.
.... or maybe not http://www.coindesk.com/bitfury-details-100-million-georgia-data-center/
Quote
BitFury will invest $100m in building a 100MW bitcoin mining data centre in Georgia