Oh, and by the way : the difference that a 70cc makes compared to a 50cc is _really_ worth it.
I've had the pleasure of owning a 70cc and a 50cc Agility at the same time for a few weeks, and I was surprised with the difference between them...
But since I turned the 50cc into an 85cc, they do not differ that much anymore... The 85cc is indeed more powerfull than the 70cc, but not so much that I would buy one again - The 70cc works with the OEM cylinder head instead of a cheap china head, and with the lighter piston the 70cc is running a lot smoother...