I'm so sorry to have kept you all waiting. Long story... :rollseyes
Well, very nice people mashaAllah. But they couldn't give me a quote as I didn't know how many copies we wanted. And most of all I didn't have a cover design to show them. Apparently, making the plates for the cover design is what is the most expensive part of producing a book i.e. how many colours will be used. I did ask for a rough quote for a 40 page (size A5) three-colour cover design, but again they said they wouldn't know unless they see the design and know how many copies we want.
The other thing they said was that if we wait for a month, they will have new machines coming, which are cheaper to run than their existing ones and so cheaper for us. The sister also said that if we can reduce costs further by doing the type-setting ourselves. Then printing the books will be cheaper. Oh, and they didn't to know anything about the ISBN.
I was assured that they will try their best to help us inshaAllah. However, I'm thinking we need to broaden our horizons.