I bought this for about $20 here on Amazon.  Don't pay more than that, there are plenty of sellers for around $16-18 plus shipping.  I bought it to use as a music stand light, and it seems that it will work out great for that.  I had seen the Mighty Bright Orchestra Light, which is really nice and has 9 LEDs and is supposed to light up 4 pages at a time, but it is almost overkill for a stand light and costs about $40.  I was looking for something cheaper.  I looked at the Mighty Bright Encore, which has 6 LEDs but otherwise similar to the Orchestra, but even that was $35.  The Hammerhead appears to be the same as the Encore except it does not have a lip on the back of it, to keep the light from shining out into the audience I guess, so you'll have to be careful about aiming it so it doesn't shine out there.  If there is a real problem with light going where you don't want it, I figured I could put a lip around the back with a piece of gaffer's tape.  It doesn't come with a bag or the AC adapter either, which was fine with me because if I'm using a battery operated light it is because there is no AC available.  If I had AC I would just use a regular stand light and plug it in.  Anyway, it seems plenty bright for two pages at a time, in fact I think some of the time you could use it on the lower setting and it would be bright enough for most situations (there is a high and low light setting, which the switch toggles between the two and off) and I'm sure the batteries will last a lot longer on the lower light setting.  At $20 I figured if it doesn't last forever, or I drop and break it, or I leave it on a gig I'm not going to be too upset about it.  It takes 3 AAA batteries which are included, and the box that it comes in looks like I can carry it around in it for a while anyway.