I'm very happy with my 3.2. I've found overall fuel consumption is about 26 / 27 on my commute with the odd bit of playing around. On a motorway cruise it'll do 33 if you're sensible.
I think it's just the "can't be arsed" factor that makes some mechanics dislike them. Yes, access to things can be tricky and the cam belt change takes practice but at that mileage it ought not to want too much attention for a good while, cam belt at 40K excepted. The 2.6/3.2 also has a bit less gubbins to get in the way under the bonnet, since it doesn't have EGR, air injection or a throttle cable!
If that price is from a dealer with warranty I'd say it's OK. When I was looking, price increased sharply with decreasing mileage. I think low mileage Omegas are getting to be in short supply. There was certainly a 3.2 elite on a 52 plate with mid 40's on the clock for 9K when I was looking back in December / January time.
Kevin