The very best price point ever is "free"!
I agree that 128-cell, 72-cell and 50-cell trays don't need to be watered as often.
Even more helpful for me is that they are more "forgiving" if I wait too long to pot the seedlings up or plant them out.
Around how many days or weeks can you leave a tomato seedling in a 300-cell after it emerges? I guess 288 cells are around a 12x12 plug tray ... less than an inch wide?