Estimating the True Costs of Home Improvement?

I am watching the home improvement and flipping shows to get ideas of the costs of upgrading my home in order to sell sometime in the future (my job will require me to move at some point and I want my home ready when and if it does).

When they show -THIS is how much it cost & THIS is the return on that investment- I think, “huh….I can afford to do more than I imagined.”

But I am wondering/doubting if those costs are true.

Do programs like that show the materials ONLY costs? or perhaps the contractor discounted costs?

Is there a place on-line or a reference that would give me a truer idea of the cost of home improvements… materials, labor, the whole thing?

On the flipping shows the owner is usually the one that does the work. Seldom is any price of labor included. Plummers charge 100.00 per hour. General contractor charges 85 or more per hour. This is in Ca. If you know how to do the work yourself home improvements are way reasonable. At the big home improvement stores here such as Home Depot or Lowes there are always people waiting for work (usually undocumented workers) I've used them alot and mostly always have very good results. They provide very good mannual labor but need to be supervised. They are good for the most physical jobs such as removing a roof, demo-ing the bathroom, yard work, pulling up the carpet, painting, washing of walls/ceiling, scraping the popcorn ceilings, etc. Remember to supervise.