I guess I just want to throw it out there, that I like the ZooMed mercury vapor bulbs because they also produce the level of heat that I like for a focused basking area, instead of needing the heat lamp combined with the UV bulb on top of each other. And while the light may still be working, our eyes can't see the difference between light spectrums, so while it can still produce light, you'll need a light meter to determine whether it's producing the right spectrum. I haven't bought one, but I trust the life span of the bulb to be one year for the correct type of light desired.
Really, all we're trying to do is provide a good source for Vitamin D3, which some people believe can be achieved through diet alone, so long as you feed the upper level brands of food. I buy Hikari brand turtle pellets. Other's really like Mazuri, but it's up to you and your price preference.
And just make sure that if you do get a bulb that runs hot, you use an appropriate hood or lamp dome based on the bulb you buy. And a small thermometer so that you can determine the basking area temperature and make sure it's running at the appropriate temperature for your particular turtle.
I have a Cagle's Map Turtle, and he likes his basking area to be in the high 80's to low 90's, while his water is in the high 70's. His tank is roughly 85% water with a corner rock for food distribution and a nighttime heat source, with a floating log in the center of his tank with the UV bulb above it with a 8-9" clearance to get the desired temp for day basking.
I hope this helps...