In the flashlight world, for the most part, you get what you pay for. So that if you pay more money, you should get a better quality, and more reliable light. It is very rare that if you were to put in big money that you would receive an ineffective and unreliable light. It is far more likely that if you purchased a cheap and inexpensive flashlight that your light has a high chance of not working well, or even at all.
I want you to know that I am a unique user, my user ID does not belong to anyone else and I don't work for any flashlight company, so my interests are not influenced by any group or company. I have personally purchased cheapy flashlights from DealExtreme. I want to be as objective as possible. DealExtreme was quick to ship, their shipping and packaging were acceptable, but decent. Their products actually looked nice. On the surface, the craftsmanship looked okay. When the lights were used however, things were a lot worse. For my uses at least, the flashlight MUST work. I may get into situations in the dark where things will become uncomfortable, and possibly dangerous if my lights fail me. Along those lines, I carry backups, now at least, not a few years back. However, I don't want my primary light to fail me, and have to use the backup. They are there only if absolutely necessary, and should not be used because the primary light breaks down easily because of the construction, poor wiring, poor soldering and bad build quality. It should only fail if the battery was out of electricity, or if the light suffered enough physical blows or physical destruction. With that, most of my lights now can suffer heavy blows, drops and crashes and will still keep working.
My Deal Extreme lights don't work. They failed me when I needed them to get out of dark places. I don't want to seem like I am bad mouthing the company or their products, I am one person after all. I just want you to know that in light of my experiences, I won't ever purchase products from Deal Extreme again. I also will shy away completely from Ultrafire. I own an Ultrafire charger which I will be replacing. I have owned 4 or 5 flashlights from Deal Extreme including an Ultrafire flashlight. The other 4 flashlights don't work anymore, and stopped working soon after I bought them. The Ultrafire is a 2AA Cree flashlight, and it will work for 20 minutes, then shut off and won't work after that. If you do end up purchasing an Ultrafire or some other knock-off from Deal Extreme, I recommend you have a decent backup, such as a selection from a more reputable Chinese company such as Fenix, or Jetbeam, or something from Surefire or HDS. The lights I currently have are from these four companies, as well as a dropin from Malkoff Devices. If you are looking for a flashlight that will be reliable and will keep you and your family safe, I recommend putting aside a little more money and getting something good. It is better that way, than to spend your money buying junk after junk from those nonreputable sources just to save a few bucks. Sorry for the rant, but most CPFers will agree that it is important to watch out for one another, even indirectly by recommending a higher quality light.