How much for a slab 4m x 4m?

Hi,
Can anyone give me a rough idea how much a slab for a shed would cost? We need it to be 4m x 4 m. I imagine 100 mm thick would be fine.

I got a quote over the phone from the concretor who is working for the builder (he can do it at the same time he is on site for them) but now I'm thinking it's too good to be true and maybe the concretor thought I meant 4 ft by 4 ft. I don't want to bother him again because of the long weekend and I sent him a text on Thursday confirming details of the job and his quoted price but haven't heard from him yet.

Hi I just got a quote for an extra slab in addition to the driveway for 3x3m at $950

Meant to add it was also 100mm

My quote is for 825 inc gst.
I feel a bit more hopeful now since maybe it's such a good price because they'll be there anyway doing other work for the builder.
Thanks for your feedback.

Thanks David,
the slab has been poured and we haven't been invoiced yet but there's been no communication about the price so I am assuming all is good!

We're really pleased. ☺