Things you need to be wary of before buying from
1) Cards are 'one shot' coded - i.e. once they have been programmed for one car, they can never be programmed for another. Used cards are, therefore, worthless. You must make sure you have a new one.
2) There's no way to program a new keycard without the correct diagnostic computer, so you'll need to budget for programming to the car. Shop around, as prices vary wildly even between Renault dealers, and you may find an independent specialist who can do the job much cheaper.
3) There's an official Renault press release over new cards that's caused some confusion over whether or not even blank
cards can still be programmed. To be honest, I can't see how they could stop it, but it'd be worth checking with the dealer to see if they're prepared to code a blank card that you've supplied yourself.
4) If you only have one card and it's broken, then consider buying two. Renault will penalise you at trade-in if you only have one card, and it's always handy to have a spare.
Also bear in mind that if you can find someone with good soldering skills, they might just be able to repair your existing card for a fraction of the price.