It'd be pretty awesome if one of the manufacturers made a frame that could accommodate several different engines, say a 125, 300, and a 600, and then sell the bike (minus engine) and engines separately. Make it nice and straightforward to carry out the swap, and there you go - buy one bike and it'll see you through CBT, A2, and the early days of your full licence, all for less money than buying a new bike each time. Nice bit of repeat business for the manufacturer because they know that you'll be buying the next few engines from them - who needs brand loyalty when you can have a captive market, much easier to work with And they could probably price it a little bit above the sum of its parts, the long term saving for the customer in theory offsetting the initial hike in start up costs... and if you make the real money on the sale of the frame and 125 engine then make an increasingly slim margin on the other two, you sustain your profits thanks to all the folks that either give up or trash the thing (or it gets nicked) before getting to their DAS Of course it might look a bit funny to have a 125 engine in a frame made to fit a 600, but I'm sure that something clever could be done with it.