A good start, it needs a lot more ventilation and some other tweaks though to be better suited as a coop, so it's not really ready... And yes your birds will have it looking light that in no time, but you still risk the transmission of disease when you buy a used coop so you should attempt to clean it as best you can, and after cleaning it I would seal all the bare wood with a good primer like Zinsser Bulls Eye 1-2-3...
BUT, the price is WAY too high, I can go to Home Depot and purchase a brand new 10x10 wood shed kit for $800 (steel sheds are even cheaper) I would never pay $800 for a used smaller one, especially since you have to take it apart, move it and reassemble the dirty thing... Around me you can find sheds like that, that are 'Please take it away for free, I don't want it' or maybe few hundred dollars...
Well it's a pile of wood, and from my perspective not much, but if you have a place to store it and transport it, it might come in handy as you tweak or build a coop...