Klipsch x10 (i)
I can get them delivered free to their address in the US - is this worth doing?
If you're making a good saving, then yes. Just make sure that you get them from an authorised seller, there are far too many fake headphones out there and they are not all that easy to spot.
+1
Despite my best efforts to convince him otherwise, my younger brother bought himself some Beats online with his birthday money. He was very content with them for about a week or so before I had a listen and could immediately tell they were fake. Obviously fake beats are much more profitable than klipsh headphones, as more people want them. The point still stands though, look at the retailer's reviews (if any) and try and suss out whether you're likely to get ripped off, as once delivered to your in-laws, they probably won't be able to tell what they should be getting (as I doubt they've ever heard the X10s).
As far as I'm aware the only difference between the two is the afformentioned remote. And they are cracking little headphones, they happen to be my in-of choice. I have the X10i.
If you're making a good saving, then yes. Just make sure that you get them from an authorised seller, there are far too many fake headphones out there and they are not all that easy to spot.
Mac mini > AVI ADM9Ts