The answer to your questions are "Yes" and "Probably not". There is good evidence that much of the wear that occurs on engines happens upon startup before the oil pressure can build up. However, modern oils are *very* good at retaining a film on engine parts, so that wear is quite minor. Modern engines can be expected to last 150k-200k miles with normal maintenance. I personally drive a Toyota pickup with 210k miles that neither burns nor leaks oil and runs like a top. Unless you have a rare classic car where you need to absolutely protect the engine because parts are scarce and pricey, I don't think the pre-oiler will be of use to you. It's likely that you will get rid of the car before you drive enough miles for the reduced wear benefits of the pre-oiler manifest. . . .

I would guess your talking about the systems that run an electric pump to generate oil pressure before you crank. They work as advertised and do create oil pressure. Now, let's do some math. If you drive your car 15,000 miles per year that is 15000/365 or a little less than 42 miles per day. If you drive both city and highway like I do you will average around 30 mph (according to my trip computer) this means your vehicle will run on average 42/30 or 1.4 hours per day. Now we need to think about starting. I drive to work and back (2 starts) go to the store (2 more) and sometimes go to dinner (2 more) thats six. Add 4 more to make it even and call it 10 starts per day. Each start involves crank time and then time for oil pressure to build. Just thinking about it I would guess 2-3 seconds, but for wiggle room and nice round numbers lets say it takes 6 seconds. So our start time per day will be 10 (starts) times 6 seconds per start or 60 seconds or 1 minute per day . Now our average day is 1.4 hours of run time or 1.4 times 60 or 84 minutes. So the percentage of time that the engine turns with no oil pressure is 1/84 times 100 or 1.19% (probably less). A quick look at the web showed the least expensive system costing $189 US. I can't answer for you but for myself it seems that If you used that money to change to a good syntheic oil that would help lubricate during cranking (1.19% of the time) and also helped during regular use (98.81% of the time) you would be farther ahead. (Hey, that was kinda fun ) Just my thoughts :^)