swillyCheapest you can do is a regular circle trampoline you see all over the place. If you wet it down you bounce higher and is pretty nice.
maxstrI've heard that the rectangle one's are more bouncer, is that true?
THEDIRTYBUBBLEAbsolutely. Rectangular, and square trampolines are way bouncier. Scout around for used ones. I found a square, 14x14 trampoline in mint condition with an enclosure, in my uncles neighborhood. The total cost was 300$
maxstrmy friend has a square trampoline and it sucks.. The highest I've got on it was no more then 2 feet.
THEDIRTYBUBBLEAnother tip. Buy older trampolines. Trampolines are being tweaked more and more so that they are safer for 4 year olds. Probably why your friends tramp sucks. Mine is probably 10 years old and it is in great condition and has a lot of kick