In my home repair business I have used inexpensive ($300) paint pumps for about 15 years. I paint about 1 house every two or three months. My first sprayer lasted 12 years! I have always been very happy with the results. I recently stepped up to a $1000.00 paint pump because we are spraying one house per month now and they are larger homes than we have done in the past. Boy was I missing the boat. The new pump is way more efficient than the cheap pump. I can spray a stucco wall in one coat if the color change is not drastic and more easily pump un-thinned latex paint (which runs less on our cold Arizona days - ha ha). Another advantage seems to be less overspray and less pressure trying to blow our masking paper away - I am not sure how this works with more pressure but it does.
We also recently purchased a small hvlp (high volume low pressure) turbine spray system to paint security doors and to use in the finishing of the vintage travel trailers we do. I have only used it on a few security screen doors and have been very pleased with the results = extremely low overspray, great finish, low material use, The turbine uses warmed air to atomize the paint which helps it dry faster. I bought the latex tip also to do entry doors and other small jobs. I found our hvlp system used for $200.00 , but you can get a decent small one from $399.00 with shipping.
Just my thoughts and ramblings on my sprayer experiences.
AZCraig