Mishk-
Doesn't seem that unreasonable, there are different qualities of double glazing units though. You need toughened of course, maybe get them double sealed (that's extra sealant in the edges).
Call a local glass supplier and ask them to quote for supply of 2 units the size you need then you'll see what the labour is, probably an online price thing you can do somewhere. To remove them they take the (normally black) rubber seals you can see around the edge of the frame out and the covers on the frame and remove the unit, pop in the new unit and press the seals back in. If one bloke can carry the unit to where it needs to be then it's a 1 man job, heavy lift but there are some big blokes around.
In any case most local glass suppliers will know someone who can do the job, or get it delivered and do it yourself!
You are reading a single comment by @Mishk and its replies.
Click here to read the full conversation.
Airhead
How low? It's not a complicated job and the units have a basic cost + the size which means small units are worse value for money. It's a 2 man job though.