modding 150W aqualight pro to 250W

[kwirky]

My MH bulb will have to be replaced in about 6-8 months or so from now and I'm thinking of stepping up my aqualight pro from 150W to 250W. Doing some research so I can create a proper $$ budget for the upgrade. I know I would have to get new bulb clips and a new ballast but the process of the modification seems a little daunting because I would have to cut into the reflector to allow for the larger bulb.

Anyone out there who's done this modification? Would I be better off to sell the fixture and get a new 250W light when the time comes to replace the bulb? I'm also considering cost. If I can modify the fixture I save $100-170, plus I still have actinic supplementation. Don't know how much $$ I'd get for the fixture with bulbs that need replacing.