check out the line of Convoy lights. Several to choose from. Very reasonable lights in your price range. Built very solid. Fairly popular. I have a few myself. Also look over on budgetlightforums. Really good info over there on lights that won't break the bank. U can also surf the for sale...
With the right batteries very cool it will run a consistent regulated 20 minutes before it suddenly off. I haven't tried it though but it seem to last while so I would say that's accurate