It depends on where you live. In my area, I'd expect $30-$40k for that. Minimum.

It depends on who you hire.

I know someone who just had one done, much smaller, no kitchen or stairs, but with a fireplace. 80k.

Post a plan, picture worth a thousand words.

Area of the country as well as labor pricing will be very regional.

@millworkman most definitely, also the layout, the height, etc, in this case, you have a kitchen, etc there is a roof (what type and does it connect to the house or not) every detail will dictate the cost factor, not to mention some Architects they can't layout decks for nothing, seen so many decks over-designed or under-designed where everything had to be changed.