I have taken the US route a few times & things have changed a bit in the last few years. Booking Stateside for a cruise in Europe has very little advantage these days due to the strength of the Pound/Euro, they are finding it hard to compete with 'our' prices. You can however pick up some great prices for Caribbean/Stateside cruises, particularly late deals etc. You have got arrange your own flights, transfers etc & if it's a great, late deal, you'll probably pay through the nose to get there, as flights become more expensive the later you book, so think swings & roundabouts. We have found in recent times, a 'very early booking' in the UK will compete/beat a US deal, but you need to be ahead of the game to catch the early worm. As for the actual booking procedure, it's no different to phoning an agent round the corner. Finally, not all cruise lines allow Stateside bookings, P&O, Princess are the first to come to mind. RCI, Celeb, NCL, Carnival among others do accept UK business.
Sometimes Yes, sometimes No. The main thing is to get the right offer at the right price and know that you can communicate easily with your agents. ... Neil.
Also need to be careful, which agencies in the states (or in UK for that matter)you use. Bookings made by US agents are not covered by either ABTA or ATOL. If agent goes bust you potentially lose everything, similarly if anything happens to your flight(delayed) the booking will not be atol covered so could lose everything. Also do not have protection of the ABTA rules on surcharges- (becoming very relevant). Having said that if saving is big enough then maybe worth risk.
Prices in uk for flycruises also tend to include transfers etc. US prices often do not.
Just to balance the view, the US agent we have used, probably the most well known one, does have advantages that no UK agencies that I'm aware can offer. You can cancel right up until final payment, no questions asked, no reasons need to be given & no loss of deposit. An advantage of this is, should your cruise go down in price or a special deal comes up, they are very happy to cancel your booking & re book at the new price. An option we have used more than once. They do require a higher deposit than most UK agents though, (about double) & finally a comment about flight delays. Surely no one books a flight the same day as a cruise, particularly if you've no possible option for an alternative back up!