Different shipping $ for west coast Let me just preface this by saying I know nothing of Drupal. I am a wordpress developer but my company just inherited 2 drupal sites from a company we recently purchased. I am using Drupal 6.25. 
I have 2 classes of products that I need to change shipping for. It's free for US east coast and $199 for US west coast.  There was a generic free shipping already set up and working but I need to change for the shipping increases. I tried using the flat rate and conditions but I kept getting "Invalid option selected. Recalculate shipping quotes to continue". I set up west coast fine. I did 2 groupings -  a main AND group with 2 OR groups in that - 'or' for the shipping states and 'or' for the 2 product classes. I disabled the previous free shipping and the west coast works fine. I set up a separate shipping for east coast just like the west coast but opposite states. It works fine if I disable the West Coast. So, obviously I am doing something that is conflicting when both are enabled.

Any and all advice is greatly appreciated!
This is not an answer, just advice: Drupal 6 has been unsupported since February of 2016 - close to 4 years now. I strongly suggest you spend your efforts upgrading to Drupal 7 right now, if nothing else because of all the security fixes (which are super important on an e-commerce site!).

The D6 -> D7 upgrade is relatively easy to do for most sites. I do not recommend going directly to Drupal 8 right now because that will be very long and painful process especially if you have little Drupal experience. If you want to move to D8, it would probably be easier to rebuild the site from scratch.