They already have crazy limits effectively. If that guy is getting tons of rare ninja then he is SPENDING THOUSANDS OF DOLLARS!

Some people have opened the 10x treasures over 10 times and got nothing but repeat crappy ninja, zabuzas, etc. Getting any decent ninja is RARE and requires spending freakish amounts of money. That is the effective limit on "buying" ninja, the oppressive cost involved.

I don't either especially since I beat my friend's Tendo Pain team a lot.

He's weak to Taijutsu and even with full pains I can wreck him with my composition. Special ninja need special education classes.