It depends what you want.
A fresh good quality turkey is expensive.
A big rib of beef with the fillet in , well unaffordable for us except at Christmas when we all chip in.
Home made Stuffing with dried apricots and real nuts / decent chipolatas and streaky bacon, sausage meat.
I just made Nigella’s Classic Christmas cake in a 23” tin (big), I kg of fruit plus glacé cherries, ground almonds, eggs, had to buy a bottle of brandy (Lidl) to use half, 4 packs of marzipan @£2 each…
Stuff really adds up, for the whole day. Smoked salmon canapés, different drinks etc.
We never get anything ready made/ ready prepped from M&S or Waitrose (or anywhere).
You can do it on a budget but if you want lots of nice stuff you can’t afford all year the overall bill can be high.