I think not.
Comet prices are going up as are twins, a pain in the backside if you ask me as to many bikes NEVER get used so they don't need parts
Go to a meet and ask someone how many miles they do in a year and they will say about 2k, most a lot less.
The last time prices cropped up every one said that they would never sell for that much and most did. An RFM has just sold for £900 ish on ebay so in my view that Comet engine is about right as is the Twin parts.
As for SS mudguards, no Pete, £250 is not a lot to you, me and a few others but most of the 12 emails that I have had today all say the same thing and that is "you must be joking, the bike only cost me £80 and as I never ride it why would I pay that".