You probably don't want to go any lower than an i1Pro.
Darrell, get the CA813. I have one and measured it against my lab calibrated Minolta T10 and it's quite close. certainly good enough for tracking light output on the Epson.
I might need to grab one of these myself.I have a CA813 too, which I've been using for 6 + years. Good light meter.
Even an inexpensive lux meter, model LX1330B (see link below), sold under several brand names, will work well for tracking dimming of a projector over time. These inexpensive meters may have more unit to unit variations in accuracy, but in one published test the model in the link below was as accurate as the CA813 for measuring a projector's light output.
http://www.amazon.com/Dr-Meter-Digi...UTF8&qid=1426033730&sr=8-1&keywords=lux+meter