If I might comment here: I am also cheap, HOWEVER, it has been my experience that putting Your change from each day into a coffee can with a slit on the plastic lid, will add up rather quickly and You'll be surprised how much You have. The other things I have done, besides using mailing tubes etc, is to make my own engine locks out of what ever metal I have lying around from other projects. Heavy cardstock works quite well for making things like nosecones , auxiliary engine tubes and the like. I hope this helps as what I have mentioned is quite cheap. Also, if You want a mini rocket to fly, check out Delta 7 Studios for their free Mercury/Redstone. I did and it makes a great schoolyard flyer.