300 gridseeds at $80 a pop that their going for now put you over 20 grand for the 90 Mh/s. That's not including everything else you need. How does it feel to know you can get a A2 Terminator scrypt asic at 90 MH/s for 10 to 11 grand?
Except he's been mining for months. By that logic you should never buy hardware as there will always be more cost efficient hardware in the future.