Since you work on Stackdriver, could you explain to me how did the pricing change last week? Previously I thought $8/instance/month was expensive, but it seems

Since you work on Stackdriver, could you explain to me how did the pricing change last week? Previously I thought $8/instance/month was expensive, but it seems like now there is a cheaper basic tier. What is a good use case for the basic tier and when will I need the premium?