I've looked on ebay to see if I can find them cheaper, but after shipping, its almost the same price give or take 5 dollars. I buy my black lights from Canadian Tire, and they don't even make white glow, $2 for a 50watt black light that produces no purple color or any noticeable light.
I know my bp can see the light a bit, but I don't believe it stresses him out all. Plus I have two UTHs on a thermostat and a rheostat so I can ditch the lamp if I want to, but it helps with ambient.