need a bit of help understand

look i need a driver but i dont understand what a flexdrive is..................................is it a driver
what is the diffrence between that and a regular laser driver

how cheap can you get a adjustable driver for

Flex driver is a driver, it will run an LD from less batteries as it boosts the input voltage up to the required voltage for the LD. It is adjustable. Info here:-
http://www.laserpointerforums.com/forums/YaBB.pl?num=1209418066

The Rkcstr driver needs additional voltage above the requirement for the LD. You can buy fixed and adjustable versions.  Info here:-
http://www.laserpointerforums.com/forums/YaBB.pl?num=1206947255

DDL driver (LM317T) needs 3v above the voltage for the LD, is adjustable you can build this one yourself. info here:-
http://www.laserpointerforums.com/forums/YaBB.pl?num=1197651171
( I could not quickly find the original thread but search is your friend)

Regards rog8811

The cheapest option in rog8811s post above is the DDL DIY driver. I use them myself, and they are very easy to build. I mostly use them for building lab-style lasers, but they can be built small enough to use in a pointer host. The flexdrive and rkcstr drivers cost a bit more, but are generally smaller and will work better in pointers.