OCUK are probably desperately trying to sell the stock they have before they supply newer generation SSD's.
The SSD's you've linked to are faster, agreed, but it's not really possible to set a UK price from that reference, other factors come into play and you cannot do a straight dollar to Pounds sterling conversion to reach a price.
Everything to do with computers in The States is cheaper than in the UK. Why this should be I do not know but I suspect it's to do with lower taxes in America.
I've found in the past that something selling for $60.00 in the USA will actually sell for £60.00 in the UK, in other words like dollar for like pound.
And that's probably more now as the dollar has strengthened against the pound recently.
And so far, I haven't found any USA online suppliers willing to ship to the UK.
You can, of course, get an individual to ship you goods and send them real dollar bills, I have done this several times in the past.
If your goods pass through customs without attracting import duty, it's worth it. If you are unlucky enough to have your parcel chosen at random by customs and pay the duty, it's hardly worth going to all the bother, the savings are minimal.
I'm looking forward to the day when these devices become affordable.
I also wonder, when they become common and demand for mechanical storage devices drops, will this in turn raise prices of conventional hard drives? Food for thought