Advice on making an offer for a domain

[EyeOhEss]

So there is a domain I am after but it is already taken. I want the domain as it works nicely with my surname. I ran a whois on the domain and based on the registrant details they want it for the same reason. There is no website for the domain so I guess its used for email addresses. 

It expires in about 6months. As I see it I have two options;

Wait and hope it expires and register it myself. The risk I run here is that they don't let it expire and they may expect more £$ as they will have just paid the reregistration fee. 

Or I go in with an offer now. This way I pretty much guarantee they won't miss reregistration but they may ask for less £$ (unlikely I think). 

Either way, I think I will be lucky to bag the domain regardless but on the off chance they are willing to negotiate, does anyone have any tips/advice on negotiations?