Hi,
You are looking at over a grand for the basic boards and DMD.
Of course why would anyone remove all the boards from a working TOM (unless they live on the south coast

) so once you get all the boards and install them you would need to start and diagnose the major fault(s) that led to the removal of all the board in the first place.
The seller does loads of deals on pinballs and fixes ones up for selling etc. A TOM is a diserable machine in most peoples eyes and demands a price premium so I doubt it will be an easy fix once complete otherwise it would have been fixed and sold rather than parted out.
So maybe allow £2000 needed ontop of purchase price of carcass and playfield, if it still interests you at that then work away but be aware it will need a lot of work on top of money.
Of course it might just need a fuse
Cheers
Ian