Jeanie, pay attention. You're in the UK. So you're in the best place of all to take advantage of the best cruise pricing. You can book in the UK. Or you can book in the US also. You get to pick and choose the best deals if you want to as you're not limited to one region.
Also bear in mind that a lot of cruise prices are better in the UK right now. The important thing to bear in mind is that you must compare cruises on an individual basis. It's rare but it can be suites are cheaper in the US and balcony rooms are cheaper in the UK on the very same sailing!
I've just booked an Azamara cruise which was around 65% cheaper in the UK to book. Yes that's sixty five and not six point five! I got quotes from our regular US based TA who didn't believe the price I'd quoted him from the UK.
Celebrity UK often have offers for UK sailings that are regularly cheaper to book in the UK. Last minute Caribbean sailings will likely be a lot cheaper when booked in the US as the big box TA's block book inventory and have to sell them off.
There's also considerably more competition in the Caribbean and many mega ships based there. So prices do look cheap compared to European sailings.
Next time you're ready to book look at UK pricing and the big box US based TA's and smile as you're able to choose the best deal. 🙂