AirScrew, you may be right, perhaps I was lucky. But my experience with online junkyards has been very good.
I'm not the least bit surprised that a dealership mechanic would respond as your friend and your brothers-in-law have. After all, if everyone bought parts from other sources and installed them themselves, they would be unemployed in very short order.
Unfortunately, they were either ill-informed or not completely honest with you. If you are familiar with Chrysler's BCMs, (and a dealership mechanic certainly should be) matching them is fairly straightforward, and if it does not work, it has a warranty, just like the dealership part would.
There are three types of BCM available for the 98 Caravan. They are distinguished by the van's factory configuration, as follows;
1. With no power locks or security
2. With power locks, without security
3. With both power locks and security
Once you have determined which of the three you need, you only need to match the catch code, 4801060, for example. The catch code is followed by a two digit suffix, such as "AF", which represents the firmware version on that particular computer.
You do not need to match the firmware revision, in fact, you may wish to pick up a unit with a newer firmware verison. In my example, if you were to find a junkyard computer marked 4801060AJ, it would be the same model of computer, but with a newer firmware revision, hence the "AJ" suffix as opposed to "AF".
I too have had many experiences with wrong parts, defective parts, and late deliveries, mostly with local auto parts stores and car dealerships. In fact, in my experience, new car dealerships are the worst when it comes to such problems.
I did get the wrong part from a Car-Part.com junkyard once. They promptly shipped out the correct part and sent a prepaid call tag to return the incorrect part.
I think you have to remember that these 'Net-connected junkyards would not do well with online sales unless they handled them responsibly. I have found that I can consistently get the part I want, with a 30 day warranty, delivered to my door for less than if I trudged through the mud in any of Connecticut's junkyards to get it.
I don't want to take issue with the whole "new" vs. "used" part issue. But if Farmer11 would rather drive for a couple of months with no lights while he waits for the dealership part to come in, then pay $300 or more plus labor for it, my guess is, he wouldn't be here looking for alternatives.
YMMV! Carl