I also work for our school district in Miami (I'm a shared tech at two elementary schools). Because most of those items usually tend to be tagged by the property control department for our district (usually if the purchase was $1000 or greater), they not only stay within the system forever but they still hold their original value in the eyes of the property control department. They even count the tagged items from before when the limit was $750 or greater).

So yes, an Apple II would still probably be worth over $1K in the eyes of the property control department. All items that are surveyed out end up in a warehouse where they're either reused by other schools/departments or recycled.

Yes, 'tis a shame. :/