15euro per 200L rain-barrel
legalize it by berlin.de/polizei/internetwache/versamml1p.php
It is cheap and light and with this thin with ropes it is so easy. You can build a tent from 2*3 rain-barrel to form the 3 legs of a corner of a (triangle) tent and to stablize each barrel by filling it with something (like water or other things you carry), you can put the barrel one into the other and then put it all "somewhere" and move it everywhere. Often/daily, we are making (legal) demonstration in a specific space (to be associated with our agenda by spreading information and for to practise the freedom of speech information and gathering), but sometime might be not allowed to have a tent.....