need advice about efficient room heater

Hi everyone,

I'm in a new house and I have my own spider/snake room in the basement, which is fabulous. The only problem is that it's cold, it sits at about 62F in the winter and about 68F in the heat of the summer. Right now it's just cinderblock walls so I'm going to hire someone to put in studs, insulation, and wallboard, but I'm still going to need to run a heater of some sort.

I tried using a space heater, those ones that look like little radiators, and ran it at medium (750 watts) for a month, but it made our electricity bill go up by an additional $40. Yikes!

So my question is this: once I've got the room insulated, what is the best kind of heater to keep the room warm that hopefully won't make my electricity bill go up that much.

Thanks,
Payton

P.S. My boa and two ball pythons are okay because I've got them in a rack with two strips on heat tape, one at 82 F and one at 94 F. They're a little stressed from the move, but are eating again. The ambient temp in their enclosures is still in the high 70s so they're okay. The tarantulas could care less about the temps, they just grow very, very slowly when it's cold.

I've been looking at this:
http://www.fanheatlight.com/
as a possible solution to that issue, but it depends on head clearance.