There's a lot of emotion and feeling being employed here. Take a very objective look at the work you think needs doing. Make a note of everything and cost it out on paper. Then get a local builder to verify your numbers or visit with you to spot anything you've missed.
It's very easy to be put off by dirt and grime making things look much worse than they actually are.
Damp:
Damp seldom requires 'a new damp proof course'. Often there is a simple fix - normally repairing gutters / rainwater pipes or potentially lowering ground levels. All relatively simple and cheap to fix. This won't be true all the time, but don't see damp and run a mile. Try and see if you can figure out the cause - sometimes it really is very obvious. Without seeing the house - it looks like there is damp in the front room on the wall against the house to the RHS. From the front view - next door has a new rainwater downpipe there. Is it leaking? Is there a problem with the drain? Has the downpipe been installed to fix the historic problem?
It looks like there is low-level damp at the back of the house but the guttering is blocked. This could be all that's causing it and would be as simple a fix as clearing the gutters (or replacing).
There is some damp evident in the fireplaces - but this is classic where a fireplace has been blocked up without insufficient ventilation being installed. The fix could be as easy as opening up the fireplace again, or just installing a grill.
Electrics. You'll see there are 'modern' recessed sockets, so this house has been rewired in it's life. Have a look at the fuse board to take a view on how recently. I'd factor in a re-wire in to the budget but you may find it just needs an upgrade rather than a full rewire.
Heating: There is at least partial central heating already in the house. I can't see a picture of the boiler or find any mention of it. Certainly the HW tank is in a useless position, so I'd factor in the cost of a complete new system.
Roof: The roof does indeed have a slight sag, but to my eye looks to have been replaced relatively recently (last 30 years?). It seems to have been re-tiled in concrete which I suspect replaced an original slate roof. Concrete is heavier and so often causes sagging. From the picture of the loft, it's possible that a couple of supporting joists have been removed to make way for the boarding out. This could be as simple a fix as adding back 2 supporting joists, if it indeed even needs doing. A very simple job, although a builder would confirm.
Kitchen and Bathroom. It's clearly going to need both. However, it doesn't matter if the existing kitchen / bathroom is a horrendous grotty mess or a slightly out-of-fashion, but well maintained 1980's affair. Your cost to replace will likely be similar in either case.
Decor: Like the kitchen/bathroom - it doesn't matter how horrendous the current decor is, or if it's just out-dated. The cost to reinstate will be the same. I don't see any reason why the plaster would need to be taken back to brick. In certain areas you may need to, but equally, assuming the damp is cured this may just be a case of stripping the wallpaper and potentially skimming.
Windows: Look good to me? They seem to have been replaced with double glazed units and whilst they're perhaps not the prettiest, seem to be very serviceable?
The 2 big unknowns for this house (from the photos) IMHO are the dodgy extensions to the rear. Building work often causes costs to spiral. If it's just a case of removing the offending structures, it won't cost much, but if you start to need to be rebuilding things cost will increase significantly.
The 2nd and biggest problem is for any house that hasn't been maintained. Damp problems especially, if unchecked for a long period of time can cause more major problems.
For a first time project, you may be on safer ground going for something that just needs cosmetic redecoration. That said, any property development is a calculated risk. By getting a surveyor or builder to accompany you on a viewing you should be able to make an informed decision.
Don't be put off by squalor internally. This could potentially be a solid little house.