Should i wait for iphone 18 pm

So guys am using 12 pro max 256gb variant, since 2020 now am finally planning to upgrade this year so should i go for 18 series , have one relative who will get me iphone from dubai , so should i go for 18 pro or pro max , or rather i should instead buy 17 series for cheaper price . And at what price can i trade my 12 pro max , it’s in working condition, 76% battery health , no scratches or dents anywhere, everything is original just i don’t have bill and box.