For the last 2 years I had a £250 stove and flue pipe shoved up the existing chimney, worked fine.
However I’ve just paid 3k for a professional installation, lining my chimney was the second worst job my team yesterday had ever undertaken.
I even had to don coveralls and help feed the liner through.
My chimney on a 1930s semi-detached involved a S bend from the lounge into the bedroom, and a dog leg from bedroom to the loft.
We had to expose the chimney breast in the loft so I could help feed it through.
In total 2 blokes on the roof, me in the loft, and a chap in the lounge pulling on a rope, and every swear word imaginable was needed to feed the liner.
I was almost tempted to line the chimney myself with a mate earlier on this year, after seeing what was involved yesterday so glad I didn’t .
Although I reckon if a chimney was pretty much straight up then it wouldnt be to much of a difficult job for a couple of capable people.