Hello Cymro:

A 15 mL bottle lasts me about 25 days and costs about $10 CAD.

People swear by Young Living brand for its guarantee of essential oil purity. I suspect that the brand is expensive and I have not tried it. Perhaps having a club membership or something like that can bring down the cost.

I have tried Dolphin and Piping Rock brands and have been satisfied with them.

I use about a total of 12 drops a night (four drops in three different locations.) There are about 20 drops per mL and a single bottle is 15 ml, and so that gives me about 25 days of use out of one bottle. The cost of a bottle is about $10 CAD.

My goal is not to use frankincense as a pain killer. The goal is to use it as an infection killer. If you think that your neuropathy is caused by an infection then give it a try. Also, frankincense likely has other effects that I am not even considering that could be a benefit.

https://ca.pipingrock.com/essential-oils...per-bottle-6366

Then there are other oils to consider too.
Eleven Essential Oils That Help Fight Lyme Disease