its on new trucks but cost much less, is this good or bad

It would a brand new truck minus powertrain (engine and transmission).

Regular glider kits, need powertrain, and rear axles.

Correct, some smaller fleets do it this way and install the parts themselves to save on final price. If you do decide to go this route, make sure to get a full record of model numbers and identification numbers on all engine and drivetrain selections or you will be into a long stop at any parts store if you dont have the information readily available :idea:

they say that the engines on these kits dont have to meet 07 standards and you also save on fuel, but is it a good idea to get one

Not sure about the fuel mileage, but you can avoid the mandatory 07 exhaust filtration system the government has implimented by getting a used engine of any fashion.

WOW 50 GRAND for an illegal refurb... How much is a new Cascadia?

Larry Dutko, GM of EPA for Freightliner is posting in this forum about 07 specs. http://www.dieselforum.org/newsarticle/article/689/1/

Im sure it is. Have you been to the FR8LNR site? It's a nice looking,comfortable truck with all kinds of new specs and safety featues.
Maybe someone from FR8LNR sales will read this and can provide the base price?