I am using their upper grade science and love it! I tried it without buying the extras but found that I needed them. The teacher's edition includes lots of extra info and instruction ideas that aren't in the lab manual. You might check amazon or ebay as that is where I purchased mine for very little.
Sent from my not-so-smart-phone
~Amy~ homeschooling mama to Will (14) Abby (12) and Alexander (2)