Is it worth it? Well, I think that depends on what you want to get out of the classes, and what else is on offer in your area.
Tbh, If you read all the baby books, I think most of the stuff you cover in class you could probably read in a few good books. When I did mine, I remember knowing most of the stuff she said, as I had read a lot of books. So if you're going purely for knowledge, then probably not. However, if you want chance to discuss ideas and explore feelings, you do get this in class that you won't get elsewhere.
I went because I was advised it was the best way to make friends, and for me I would happily pay the £250 again, and more for the friendships I gained from the class. Over 6 years on, I still meet my NCT friends weekly, our children are like cousins to each other, and it is a tight nit little group. It is lovely. Someone once said to me, that the bonds you make with the NCT class, are quite unlike any others and that is true. Because you go through that journey together, it can make for a very different relationship. It sounds odd, and possibly impossible to understand unless you've been there which I think often explains the divide. I didn't understand it until I'd been there. So for me, the friendships I have got have been worth every penny (if only in the free babysitting I've had since )
But some people don't gel with their groups, so if you're only going for that reason it could be a complete waste of money.
Also, you have got to ask yourself what other opportunities there are to meet other mums? Some doctors surgeries / hospitals offer weekly classes, where you might meet people. Mine did not. The NHS class consisted of 30 couples on a one day course. I don't think I spoke to anyone that day - not bar the pleasantries. It was not conducive to meeting people. Yes, I could have met people post baby, but it was in those early days that I really needed a friend to speak to! It took me months / years to really get pally with other mums and its still not to the same level of friendship that I gained from my NCT class.
So, in all was it worth it? for me, yes. Would I pay again? Definitely. But I can see that it is a gamble - and it will depend on whether you can afford to make that gamble.