Is inventory cost the same as Cost of good sold? I believe it is but would be grateful for comfirmation.

No. Inventory cost is the cost of raw material consumed during a period. Inventory cost = Beginning raw material + purchases of raw material - ending raw material. Cost of goods sold = Beginning Raw material +Purchases of raw material + direct cost incurred - ending raw material.
The difference between the two is direct cost incurred or conversion cost incurred.