Can anyone tell me what model Marin the below bike is and what year it is etc?

Never had a Marin and not sure of quality? Good bike?

Is it a Std Mount Vision circa 04' or so?

Maybe even earlier than that – could be a 2000-2001 Mount vision – Check for cracks if you but it at that age 🙂

Bit of a marmite bike – I had a MV and didn't get on with it. High BB, bit perched. New ones are a bit more slack head wise 🙂

Great place for a bottle mount also! I love abit of grit with every sip!

It's a single pivot TARA bike, which dates it around 2001-2003.

It's an 2002(?) – 2005 Single Pivot Tara FRS, with adjustable travel rear end – attack-trail/wolfridge (there was another I forget), name were different but the frame was the same just different spec levels.

Nothing wrong basically wrong with them, though there have a rep for being very quite high position (your on not in the bike) due to the high BB. Not bad bikes but nothing fantastic, and Marins have a rep for being creaky.
Wouldn't pay a lot for it though…

He wants 400 for it but claims it owes hime 1000. Think i'm going to leave it.

Well I got £270 on ebay for an 07' Marin MV frame 2 years ago – I'd tell him to go fish 🙂

Might have cost him a £1000 initially but it ain't worth that now.
£400.. depends on the spec & wear but probably not worth it.

I have a 2007 Marin frame that I don't need it cost £1100 new, plus £300 or so for the RP23 ontop, might be worth £250 now [EDIT: opps apparently maybe not]… what it owes you has bugger all to do with the value.

I'm sure the rear shock isn't the original either…

That's a Rockshox Bar or Ario, which isn't the Fox Float it was likely purchased with.

I had the attack trail version, wasn't the most confidence inspiring bike I'd ever had and the thing creaked like you wouldn't believe, you could hear me coming from miles away!!!

Yep – pretty sure it's a 2002 Wolf Ridge. I think they went to the Quad Link in 2003. IIRC the Attack Trail was a different spec but available in white instead.
Check the rear swing arm for cracks where the lower brace welds to the underside, also check the back of the seatpost for small cracks as well. I had replacements for cracks in both those areas.

2001-2002 Wolf Ridge – came with the RS SID rear shock as standard and I think it was the only one in the TARA range that had it.

£400 is very over-priced.

I'd leave it.

For £400 you could bag yourself a fully built 2002-2004 Spesh Enduro which is a much better bike.

The seller would get much more for it if he split it.