If you are buying the domain name of which part is registered as a trade-mark, then you are taking a bit of a risk... Is there a reason that you specifically need that name? It would probably be safest to try and find a different one, unless you specifically need that one.
Certainly a risk Back in my university days bought 2 domains with a trademark in it but had permission from the owners of the UK trademark but got a letter from the solicitors of the USA trademark owners (who were currently also suing the UK trademark owners) and eventually sold them to the US company for about $8000. On the other side of the coin, having worked for a blue chip company until recently, they had a whole division dealing with intellectual property rights infringements (many of them domain names) and in addition to seizing the domain name they would typically then charge the registrant $10,000 - $20,000 in legal costs and had no issues of going to court for the money (and then adding court fees on top)