Nova X-series with Collimating Lens

Hey guys i was just wondering if i were to get a Nova X-series laser (50-100) and then get this http://www.novalasers.com/NOVAstore/pc/viewPrd.asp?idcategory=5&idproduct=10.
Its their lens holder for the X-series. If i used the collimating lens would i get more power and would it burn better. Say it does, then i could get a lower powered laser and the optics to increase the burning power. Right?

The lens holder is for the X Series.

No, the lens just focuses the beam to a very small point. At this point, the power density is greater so it will burn better. The power will not increase, though.
Any magnifying lens will do, and really, the focal length of that lens is so small (a few mm) that it will be useless at more than a centimeter.

You can use a convex lens to focus lower powered lasers too, and this may allow them to burn, but don't expect to be able to cut through electrical tape with a 5mW and a lens.