@babyguffingtonstrikesagain
I can't believe it! A beef wellington for 4-6 people for £60??? I know that for lots of people M&S is their go-to for xmas food but that's crazy right?
M&S is well known for costing more, I'm not sure why you'd be surprised.
I've done the 'M&S Christmas' before lazy We got a lovely turkey crown (two of us), pigs in blankets, pre prepared parsnips, carrots, brussels with bacon, and obviously mince pies and extra thick brandy cream. Probably a couple of other bits I've forgotten about.
The crown was amazing
The pigs in blankets I couldn't tell the difference that would justify the price
The veg was great in that you could shove it in the oven, no peeling or mess or cleanup 
The mince pies and cream are a must, I won't buy them anywhere else.
I think there's an element of it being 'expected' that prices will be high there, especially for meat. Ion't think I'd go as far as to buy a beef wellington or joint there unless it had extra stuff that would save me a job (i.e. stuffing and the skin pre prepared with herbs etc). £60 is a lot. Donald Russell do one the same size for £55, but they are guaranteed to be outstanding and if I had to choose what would be more likely to be worth the price, I'd go for DR every time.