Without reading the whole thread I just thought I'd chime in. To keep on top of my costs I made an excel spread sheet with every single ingredient I have purchased priced out at $/ounce. I factor in tax, then divide $ by mass/volume.
I eat the shipping cost(and shouldn't, but we are small scale hobbyist soapers with other jobs..... so I rationalize it)
I get Olive oil at Costco. Right now it's 31.99 for 6L. (or $0.15 per ounce)They also don't charge tax because it's a food product. Getting non food grade olive oil from NDA or other suppliers will result in a 13% tax charge. Those little bits can add up over time.
I get Lye from home hardware and it's $0.25/oz. No shipping cost on that one.
We live East of Toronto and my brother lives West, so when we visit him we stop off at the NDA warehouse to pick up and save on shipping. Last trip save me over $40.00.
When buying EO's look closely at the pricing. NDA pricing is not consistent based on size. They seem to give a HUGE price cut when jumping from 100mL to 500mL, but not much of one from 500mL to 1L. They price some things strangely, so just keep checking around.
I'm keen to go through this thread when I have a bit more time on my hands and see what else I could be doing to pinch the pennies.
Peace.
Edit: Almost forgot. Costco had Avocado oil on sale at 9.00 for a 1L bottle. Kills the price of all the suppliers and again... NO TAX I'm waiting for that one to go on sale again.