The 30 Large Shield Extender IIs sold quickly and after a day there is only 6 left. Profit margin was about 650K ISK per unit which is similar to the Invulnerability Field II margin. So about 20 million ISK profit for a small batch.
I plan to expand operations as I've found a steady supply of BPCs now. I ran 20 invention jobs on Invul Fields last night and got 8 successes, 2 below average. But I can get 40 fresh BPCs every week now, and another 40 Large Shield Extender BPCs per week as well. The goal is to get into a flow so I'm producing a set number a week so I can standardize my buy orders and simplfy my life.
In the meantime, my blueprint copy supplier is also working on some ship Moa BPCs for more Onyx invention.