Assuming the foundation doesn't need any work, but everything else does, I wold estimate around 100K for something like this. You're going to need to get a GC (or GC it yourself if you can). You'll need a building permit and all the trades will need permits and inspections. The basic order of operations is:

1. demo/trash out
2. Roof
3. framing
4. plumbing (need permit)
5. hvac (needs permit)
6. electric (needs permit)
7. framing inspection
8. Walls, sub floors
9. Paint, flooring, cabinets, fixtures, windows, etc.

You'll also need to do some exterior work at some point - those steps look like they need work.

I do this professionally, and I can also tell you that no one who does this actually has the money to do it themselves. It's all borrowed money. The standard thing to do is get a hard money loan (short term, high interest rate) to buy the house and rehab it, then either sell it or refinance into a long term mortgage once the work is done.