For me, were it to be a days work if done trad (say 8:30am till 3.30pm) then I would be up around £200.00 minimum, particularly on a posh club.
For a full days work on one account there ain't no way I'd go in lower than that.
But of course it really does all depend on the kind of area you are in.
As I use WFP, and providing access wasn't too big an issue then you are talking about a mornings work, less on repeat cleans, or rather an easy mornings work.
By and large I charge approx £1.00 per standard window and make an allowance for things such as access.
My above price is only based on the fact that you say it is a days work.
My price would be the same for WFP, I don't price cheaper just because it is quicker!
Were I you I would go in roughly 25% higher than you would normally charge, if you don't get it at that price then it isn't worth having...honestly!
I personally view these kind of jobs as the cream on the top and for me they are by far and away my best payers.
But it is tough if it is a job you really want to get
Ian