Yes, but how could've players know that there would be so cheap Kakuzu?

Does that means that everyone should wait for a few years in order to get very cheap deals?!

And what is cheap actually? Maybe there will be cheaper one later.... This could go on forever....

Maybe they should wait with no ninjas (and lose every battle) untill they get them for free (you will not get a good ones for free, and even if you get them they are obsolete by the time you get them), or what?

Also, which ninjas to take? We spot someone nice with great BT, and we collect money for that ninja. When we finally collect enough money, they created better ninjas, and this one is rubbish now. Take old one, or wait for a new better ones to become cheap? You wait for a new ninja to be cheap, but they create better one. Now you wait this one, but they create newer better one,... and so on...You never get any ninja. :)