Homeschool access to public school resources

When you jump into homeschooling, it doesn't take long to figure out that resources are priced for schools, not individual homes.  Schools purchase licenses to all kinds of online resources, for example.  Discovery Education, Discovery Science, BrainPop, NovaNet, Colonial Williamsburg Electronic Field Trips (EFTs) and probably quite a few more that I don't know about.  These licenses cost thousands of dollars per year for a school/district to subscribe to.  Now, some of them are made accessible to homeschoolers through a Homeschool Buyers Co-op (a wonderful resource for textbooks, subscriptions, software, field trip info, etc.).  For example, I was able to buy a yearlong subscription to Discovery Education for about $200.  On the other hand, I pay taxes that support our public schools, but use far fewer of those dollars than a family that actually attends public school.  I don't require their textbooks, their services (in terms of teachers, libraries, therapy, tutors, etc.).  It doesn't seem like a lot to ask for logins for their online subscriptions.  When I contact our school district, I'm told it can't happen.  That their licenses are "site licenses" and the use of the services are restricted to the particular building for which they were purchased.  When I questioned a little further, though, teachers are allowed to login through their laptops from their homes.  If the teachers can, why can't I?