It won’t get any cheaper with the latest JobCost Changes. Researching BPOs to 10/20 has become extremely expensive, even in facilities with low taxes and a low system cost index.
Friendly reminder: the research cost price increase from the recent patch will make it insanely expensive to research new BPOs to maximum efficiency, those BPO’s prices will only rise. Already 34B if one would want to buy them all individually from the contracts right now.
Update: Amarr, Caldari & Gallente BPOs have been sold! Minmatar still available (7B for all 3). Be quick!