Tickets for Nintendo theme park in USJ

I've checked the tickets and I know you need to get a ticket time slot but I want to go in August so I'm worried it will be supercrowded, so what do you recommend me to do? I know about express tickets but they are around 18.000 yen, but it's a bit expensive isn't it?

Any tips? or what would you do?

Dont go if you cant pay your way inside, they overcrowd the park on a regular basis. And once you are inside without special ticket you will get nothing of the main attractions.