Umarex baby desert eagle question?

Hi I am going to get a co2 powered bb gun,I have a few questions about one.I have been browsing pyramydair.com and I saw a baby desert eagle for 40 clams.Now I might get it along with 15 co2 cartilages and 1500 or so bbs.Now I am having a hard time trying to find out how many shots I can get out of a co2 cartiegde and if this gun is good or not.I know its not blowback and that some parts are just for show like the hammer and safety near the back.But at 40 dollars and 420 fps is it good for just shooting cans in the backyard?I know that you might recommend a 15xt or c11 but I really like the desert eagle plus the normal co2 desert eagle shoot for the same fps is is 150 dollars and this baby desert eagle is good for my shopping limit .What do you guys think?.Feedback will be appreciated.