You're in Holland where theres tons of pretty nice old road frames to be had. You should just buy a fixed gear wheel set, with a flip flop hub(means you can switch to freewheel) and a decent crankset, altogether this should run you 350 euros or so. For around 20 euros you should be able to find a nice old racing frame with horizontal dropouts. The rest of the parts should be really easy to find too(stem bars seat brakes etc...) If you can find a nice old frame you'd probably end up with a much better quality bike than if you bought a charge. Also, for around 600 euros you hsould be able to get a brand new bianchi pista. I think they were 650 at lohman's in Amsterdam.