Well, I suppose it is too late now - but this is how I see it.
Handing it over costs you money - and it is obvious they wanted it.
If you were intruding on the area of trading covered by their trademark, it is a "gotcha", but, despite the legal threats, "rolling over" too easily is never a good idea.
A minimum of ceasing and desisting is required, so, if you are intruding on their trading area, you take the site down, or change it to dress-making, or something else that is nowhere near their trading area.
Now, just to give you an idea of their costs, the specialised solicitor will cost them at least £250 an hour, probably £600. If they have to take you to court, they want to win, so they might also employ a barrister - that's £625 an hour. To prepare a court case they will have about £2k of lawyer costs, not considering the work going on inside their office putting the evidence together. And remember, there are time considerations - Bill Gates made millions because it took years for the cases against Microsoft to come to court.
That telephone call to you probably cost them £125, and they consider that well spent because you are "rolling over".
They were remiss in that they did not register the name for themselves. They want it.
If it were me, I would offer it to them for about £1,200, which is about half of what it would cost them to recover it through the courts, and then reduce that a little during negociations - but not much.
This is business. Even the lawyers have an obligation to do things the quickest and cheapest way possible for their clients. You may not have a hope if it goes to court, but you owe it to yourself to squeeze as much as possible out of the situation.
Remember, those people are paid to intimidate you - but as professionals, they are unlikely to "send the boys around". They want the quickest, cheapest solution. You handed it to them, but you might have done better.
As an incidental matter, it occurs to me that it would be a good idea to call the lawyer's office and find out the hourly rate - or, if you are really cheeky, ask during the telecon!