If you are reading this then don't type how hard it is. And don't type how you wish you had more money. If you know me personally then don't even try my initials ;).
It's not really that hard, the boxes actively make it more difficult until you unlock the nuke, at which point you just duke the enemies for 20 seconds or so and then nuke them all. wave 45 at the moment. I have over $8000.