Grados have always been very expensive over here
To be fair to Grado, that's the price they were selling the older models for as well, so no price increase. Also, some of the RRPs have actually come down over the last year or so. The 225i was going for £299 a while back, and some places where asking for £899 for the RS1i
Importing from the USA is hard as Grado regulate their dealers quite strictly. No one is officially allowed to export to the UK (or elsewhere I guess) If you are able to get one imported, I wouldn't be surprised if Grado refuse to honour the warranty.
The only official way to get a 'cheap' Grado is to buy an Alessandro ...