63 plate 1.6 ignition

[Hellsd7]

Hi all,
My caddy vans ignition barrel won’t turn to start the van.
I can get the steering lock off and wiggle the key but it won’t turn fully to start the van.
Are there 101 different things it could be?
If not, does anyone have a rough idea of the cost to get this fixed please?
Or if there’s anyone in the South Lincs area who anyone recommends to fix this please
Thank you for your help