Why? Without looking it up, I'm guessing the Dodgers have maxed out the set penalties (international pool, draft picks), so at this point, all they're doing is paying dollars to spend dimes. And if Sasaki, Yamamoto and Ohtani are bringing in the money to pay those overage fines, they're really setting themselves up to be the team for which Japanese kids dream of playing for decades.
You're already braying about the Dodgers signing an African player. Anybody else could build a baseball diamond in South Sudan, and start training kids to play baseball. If the Padres weren't in an ownership fight, and maybe spent a little more judiciously, they'd have the money to sign Tanner Scott. They're also going to lose Jurickson Profar to somebody with their dithering, and we'll all cry that baseball is broken, again.
The Dodgers have built the prospect machinery to add their initial round of free agents to, then build a brand in Japan. That's exactly what MLB wants.