1 - there are very good professionals, but they aren't cheap and have all the work they need
2 - an amateur can always decide to take economically irrational amounts of time on a project; a professional can't.
So the result is that as a careful amateur you can end up with a job you probably wouldn't be able to convince yourself to pay for.
We can probably all agree that the worst case is the careless amateur....
Even on the financial level tradesmen here in Australia are so overpaid (compared to everyone else) that it makes sense even for me to do it myself. My house was painted by "professionals" just before we moved in (purple??) and it cost the previous owner $20,000. My wife and I repainted it white (this required 5 coats of paint) and it took us two weeks including the time I had to spend getting the purple paint off the windows and floors and patching all the holes that had been painted over.
Tip. If you are selling your home don't paint it some unusual color. I managed to buy my home $200K under its actual market value and quite a bit of this was due to the crazy way the place has been painted.
I have used gray before to go from red to yellow as it seems to work in fewer steps.
I am not sure that description is apt. Underdelivering is only rational for the painter because the client won't be on the market long enough to gather sufficient information. The client is getting cheated, and it creates a lemons market, the fact that it is a Nash equilibrium does not make avoiding the entire thing irrational.
And the entire thing has parallels on software development...
An amateur painter will often spend far more time than any reasonable estimation of the market value of that job would justify. Part of this is lack of efficiency and experience, but another part is doing things with sharply diminishing returns. For example, you might apply expensive techniques to inexpensive materials, in a way that would not make for a viable business.
Put it another way - amateurs can easily arrive at a finished job (of painting, in this case) that they would never be able to convince themselves to pay market rate for. This is irrational in certain restricted senses.
For what it's worth I don't believe that "lemons market" is accurate for painters in general, but I'm guessing there is a segment of it that meets your description.
If you're looking at it from a economic standpoint, to be considered irrational, the tradeoff between the value of time vs the cost of hiring a professional would have to assume that the value of the time is greater than the value of the professional.
I always hear this compared to "what is your hourly rate in your job" or "my time is worth more than that", but I think for most people this just isn't a fair comparison. Just because I can spend 10 hours painting my room and I make $x/hour and it would cost <$x to pay a professional, does not mean I would be able to actually generate an _incremental_ $x per hour by not painting and hiring the professional.
For most people on a salary (where your pay is fixed no matter how much time you put in), their time outside of the job is, in a very real sense from an economic standpoint, valueless, and it would be perfectly rational to spend that time yourself, no matter how cheaply a professional could do it.
If you're looking at it from a economic standpoint, to be considered irrational, the tradeoff between the value of time vs the cost of hiring a professional would have to assume that the value of the time is greater than the value of the professional.
That’s an oversimplification, and not the argument I was attempting.For what it’s worth, I don’t think we are really disagreeing much.
On the other hand, coming from a country that takes its trades extremely serious, I was shocked about what I observed every time I visited the UK. It seems the expectations vary drastically between different countries (though I'm sure there are quality professionals in the UK too).
House price / rent value is basically dependent on location. Money spent on fitting is generally wasted.
There are a lot of great craftsmen in the UK, but they tend to work on a subset of jobs - restoration, passion projects, really high-end stuff.
PS: This is also a direct result of ever-rising house prices. If land/house prices are consistently rising, it often makes more sense to let lots stay empty, rather than building (which is always a massive risk). It also makes sense to do any repair or upkeep work as cheaply as possible - since in a rising market, the only way you can lose money is by expensive development costs.
On the sand paper front make sure to spend money there. Cheap sandpaper last 2 nanoseconds and does a terrible job.
If you want a good result don’t skimp on the tools. Buy good quality brushes, rollers, filler, throws and paint. Also buy an edger to cut in the walls and ceilings. One final tip buy some of the disposable plastic liners for the roller tray so you don’t have to spend time washing out the tray at the end of the day.