You get $10 every 15 seconds from a $1,000 printer.
60 seconds / 15 seconds = 4.
Which means $40 a minute.
It will then take 25 minutes for you to produce $1,000 to pay off the printer you planted, after that, everything is profit.
However, that requires you to place the printers, and hope nobody raids you for 25 minutes before you can start buying stuff.
I've been sitting in a corner with 2 printers for what feels like an eternity, and I'm just now halfway.
Once I get 1,000, I then have to wait another 20 minutes to buy a gun. If I die during that time and lose my gun? Money wasted.
Either reduce the price of the printers, or increase the payout.