gn,
It depends what you want to do. Bane is right about the pool. It requires a permit, specific type of soil back fill, and a compaction certification to get rid of it.

As far as how much it cost to rehab that varies. Some people could live in it pretty well just re-painting and fixing a few things and going on to add the usual personal touches. Those holes in the arches are for built ins but could just be drywalled closed too.

The roof and exteriior look good. A great roof is big when buying a fixer. I think it is probably a solid house. It looks to me that most of it is serviceable. Maybe it is even pretty sturdy work just rough looking.Take the kitchen range hood, very tacky to me.The kitchen would be helped tremendously by a good full tile backsplash,different paint and that range hood fixed, maybe moulding on the top of the cabinets. If the flooring is suitable,to the buyer) and excluding the pool and landscaping maybe 15-20k could do the minimum . Decent flooring installed, if needed, could easily be that much again.It looks like the owner was happy with the flooring because the base boards have been painted. I am assuming the rooms and areas not photographed are finished to the same degree. In any case, very easy to drop 60k-100k just to get it up to speed, paying for labor and materials, including the pool and a modest overhaul of the yard.

If there are disasters all over and they only put the most finished areas in the photos it would be at the high end of that or even more. Often times the work already completed, upon close inspection just looks too tacky for most people. Hard to tell from the photos.