Painting the interior and exterior will not increase the value but it will decrease the time on the market and improve it show value.
New carpet, might not increase the value, but makes the new homeowner realize that I will not have to replace the carpet.
I just had a $30K pipe re do on my home. The cast iron pipes after 30 years rusted out. I live in a slab foundation home. They came in and tunneled under the foundation and replaced all the pipes with new PVC and even made new connections and piping to the city line.
Well, I thought that this would increase the value, but it does not, it just insures that the pipe system is in good working order and this will not have to be done again. But, no improvement in market value.
I can think of only a swimming pool that increased the market value. As a good realitor and he/she will tell you the exact things that do improve market value, Not many at all.