Well, you can try the Joyetech eVic. It is at $130, I believe. You can dial in the voltage and whatnot to hit your sweet spot. I have not used one, but it is on my radar. I was just reading a post about the variables.
I have the Joyetech eGo with the 650mAh batteries and the are lasting me about 6 hours or so. 3-4 if I am hitting them fairly often. I got my starter from VaproKings.com as they are having a sale and i have a coupon code for another 10% off: VKBC http://www.vaporkings.com/Joye-eGo-kit-in-matte-black-Genuine-JoyeTech-p/ego-kit-black.htm is the kit I got and it is $69 and change, making getting 2 kits below your $150 price range.