Thanks for the feedback. I will plan on changing rollers as I change from primer/first coats to top coats (I was afraid of the results w/ the crustiness, so I had been changing them for every coat on every surface!) I know they're inexpensive, (about $3.50/ea), but it would add up if I used a new one for every coat of every surface (5 rollers per room!). Also, it seemed like such a waste to spend more time fighting traffic, finding a parking spot, and fighting my way through the continent-sized Home Depot to buy a roller that I would throw out two hours later. I will try one of the 'used' rollers tonight (it's only been a day, and I am doing first coat of finish paint with a second coat to be done on top). If it seems OK, then I will probably use on roller for primer and perhaps first coat of finish paint, then a new roller for the top coat. That brings me down to 2-3 rollers per room.
Thank you for responding so quickly. You guys do a great job with this board! I check it out almost every day, and usually find something helpful (especially since I want to remove paint from brick!!!! - Yes I have done the search and know all I need to know on the subject!)