If you only going to keep it for a couple of months to get some experience then I wouldn't get an RS125 TBH. They are expensive for what they are and chances are it'll need a top end rebuild sooner rather than later and if you should happen to bin it then the fairings will be the same price as any other race rep type road bike IE bloody expensive.

In a couple of months the biek market will start to drop and less people are going to want a race rep for a winter hack to selling on might be difficult too..

Just my thoughts..