Buying an old house and fixing it up.....
You gotta remember that those TV shows, while technically called "Reality TV" are in fact, NOT reality. They're entertaining and you can get some good ideas from watching them..... the best idea is that you can make a crappy old beat-up house look really good...... with the proper investment of time and of course, money. Money doesn't seem to be an obstacle to many of those folks..... but here in the real world, folks like me have limited resources to work with..... but even that can be dealt with in a reasonable way.
Don't let them misguide you. It's not that easy, but it can be done, and not break the bank in the process.
On the flip side.... here's my experience. In NC the sale of a house is contingent on a termite inspection that will reveal if there are live bugs, or if there have been bugs there. Its a Law that every house being sold must be inspected. I went a step further before I bought the last one I picked up for rental income purposes. I hired a certified house inspector. That way, there were no surprises.
But lets go further back..... 30 years ago, my wife and I bought a house that was close to 90 years old at the time. It had been rented out previous to our purchase. Being a bit on the handy side of things I figured I could do 90% or more of the needed work. The house had good strong timbers and no termites so we bought it and moved in. We selected the room that we wanted for our master bedroom and set up camp in the other one. We started working on the house, one room at a time as we had the time and money to do.
Work consisted of sometimes simply painting a room. Other times it involved tearing out the cracked plaster walls, insulating the walls and installing new sheet rock. We also used a chainsaw to cut out the wall of a closet to make it a 6' wide closet with bi-fold doors rather than the 24" door closet that was there to start with.
We painted, replaced wood, installed sheet rock, built walls, tore other walls out, installed a central HVAC system, eventually re-plumbed the house, and even added on with a first floor master bedroom suite, enclosed the back porch to make a laundry room, built a deck and added on to it a few years later, and the most fun project of all was to remove the chimney from the roof top to the floor level in the first floor den.
We didn't have a big budget for any of that. We took it one room at a time and did one project at a time. As we completed one, we were thinking about what was next and started planning for that. As it turned out, we're now kind of in the process of going back through the rooms.....since our daughters have moved out, we have painted and reworked those rooms back to a semblance of normalcy. No more weird colors.... although it did take several coats of paint to cover some of those colors..... they're gone now....
There is much satisfaction from buying an old house in fair cosmetic condition and working on it to restore it and put your mark on it. If you have to hire someone to do all the work, yes, it can turn into a huge money pit pretty quickly. SO, it would pay for you to have some skills in construction before you decide, or be willing to learn some things.
For example, I had never done any tile work previously. But when we were discussing the addition, we knew we wanted tile in the bathroom and in the entry hall. I went to the home improvement store and watched a demo class on how to do tile. I purchased the tools, the saw and the cutter and the trowels and other things to do the job right. Same thing with the trim carpentry and painting. Buy the tools that are pro quality. Even the cost of the tools will be much less than if you hired someone to do the job. I followed the instructions on the laying of the tile and the job came out really nice. I even installed electric heat under the bathroom floor. I'm an electrician by trade so that was easy. I did tile, paint, trim carpentry, plumbing, electrical, demolition, ....practically anything and everything I could to avoid hiring a contractor to do the work.
I did have a general contractor on the addition to do the foundation, the framing, the sheetrock and taping, and the roofing, as well as siding. If I wasn't sure how to do something, I asked the general contractor for advice and tips. He never refused to assist me. The rest, I did. It took a bit longer to do it all myself, but I enjoy seeing the work and showing off my skills to people seeing our house for the first time.
Done right, a rehab project on an older house will look good, and give you the satisfaction of knowing you did the work.