Buy any TWSBI pen (lowest cost is $19) and get your pick of one 30ml bottle of Birmingham ink plus any Nemosine pen in stock. It’s a good thing.
https://mailchi.mp/birminghampens/ebonite-model-a-fountain-pen-800043?e=0026eb3753
https://mailchi.mp/birminghampens/ebonite-model-a-fountain-pen-800043?e=0026eb3753