That all depends on if you are willing to throw £68 away if they do end up damaged and unusable.
If you are willing to do the above if you have to then buy them however if this sounds like a lot of money to throw away (seeing as its just past christmas and not hit payday) then I would suggest you either go to view them (if this is an option) or you play it safe and buy NEW.
These are just my opinions though mate, hope it helps though