How many games do you need to be interested in before you buy their console?

Honestly just one exclusive does it, I can always sell the entire thing later.
Honestly just one exclusive does it, I can play the right game forever.
Just one does the purchase, I trust there will be others to follow.
Two or three at the very least, then I can justify a purchase.
Four or five, I think things over awhile before I buy one.
Five to ten, I'm not buying an unproven system.
10+, I only buy hardware that will continually be supported over the next decade.
20+, I buy last-gens when I can just enjoy the entire library at once.