My Theory: RITE — Ritual Instrument of Textual Esoterica

[Bluetoes101]

An issue is the MS was something like £10,000 to produce, and a years work.

Where does that estimate come from?  

Sorry for delay, works crazy atm so I only manage to get here on weekends

If it was a "passion project" of someone it would be like you say, an expensive vanity project (which most wouldn't undertake on a whim). However if paid scribes were involved it would be a lot more. An estimate I saw was 2 months wages. In the 14c, 5-6 months wages got you a cottage. Try finding a cottage in England for under 300k today.. so I guess it depends how you slice it. It's probably where "100k!" estimates come from.. But I think its safe to say "fairly expensive relatively" whatever the final calculations are, supposing paid scribes.