who fail to learn from history

"but this time's diff'rent" everybody knows
this climb in value's never gonna stop!
the old refrain so feverishly goes
until at last the bubble's gotta pop
for tulips or for houses, the same rule:  
the value's what a buyer's game to pay
you've only gotta find one bigger fool
to pump the market each step of the way
at equilibrium, all trade's for needs
and speculation couldn't make a dime
you'd live in houses where you hold the deed
but speculators need change over time
where labor's not as valuable as cash
the system's always prone to boom and crash