Hi,

I would check:
marktplaats.nl
2dehands.be
ebay.com

But be warned: buying from these places and not getting a bad blade requires some insight and knowledge on what to buy and they will probably need some work. Cleaning, rescaling, honing, etc.

If you want a good blade that needs no work you can also check the sales section in this board and see if some member sells a blade that you would like in a shave ready state.

Good luck!