I love my Fusion. It has proven quite useful for night fishing, camping, and working in the attic.
I run it with NIMH 1800 MAH batts, so operating costs are very inexpensive for me. I just keep an extra set of batts in the carrying pouch when I take the light on a trip. That has worked out really well so far.
As far as price goes, you can get it for $39.95 at BotachTactical.com. Be forwarned though that some folks have run into issues with this supplier. However, I purchased my first Fusion from them and had no troubles at all. From what I understand, they seem to do OK on smaller orders, but can have problems with larger orders. If it were me and I only wanted one unit, I would get it from them. The price is just too low to pass up. If you don't want to deal with these folks, i too have dealt with Paramagic1 with great results.
As far as the improved battery cover latch goes, don't worry if you get the older one. You can just email the manufacturer to request a free replacement. Heck, I came out pretty good on that deal. I had to request improved battery compartments for the 3 Fusions that I purchased. They sent the replacements along with 3 complementary yellow Photon 2 lights. Then they goofed and sent me 3 more replacment battery packs and 3 more yellow Photon 2's!!! Then they sent one more battery compartment and Photon 3 light. The same thing happened to a friend of mine who requested his replacements at that same time. You might not get all the extra replacement stuff like we did, but I bet you would at least get a free Photon light. Not a bad deal! Just have to baby the old battery case cover/latch until your replacement arrives. That is what I did. The replacements arrived before the old latch had a chance to fail. Most likely though, you will get the new and improved latch as it has been available for some time now.
Best of luck to you!