I agree on your points there viirkokka, it is a lot of cash , and with it being your first marker you want to get it right. The markers you are looking for are good choices, look after them and they will last for years to come.
However, the Ego 08's you have been offered are at the most a year old or less. Some are most likely are still under warranty, and only just breaking in.
Ego's are very reliable, the worst thing that could happen would be a blown noid or board. Anything else would be an easy fix, mainly o'rings or detents.
If your worried about the cosmetic side, just make sure you have very recent pics of the marker.
I can vouch for any of the Wildcat members selling Ego 08's, (Game, Niall) they are all in full working order, and if it helps, i can do a full strip/clean and service to them before they go out to you.(this will have to be after the 11th jan, when i see the lads next)