sounds like you’ve gotten the hang of things. the T2 BPO’s are artifacts from WAAAAY back in the day when t2 blueprints first came out. the only way to get them was through a lottery type system that was, frankly, a total mess. they removed the ability to get the BPO’s shortly after and introduced invention to get the bpc’s.
the few t2 bpo’s that you still see around are the leftovers from that lottery system, no new ones are likely to ever be introduced. hence their massive price.
on top of that, due to the relatively low component count on most t2 manufacturing, the savings you get from having one isn’t actually that big compared to manufacturing. for even the most profitable ones you are still looking at about 10-15 years before you start making an actual profit on them. and thats assuming 24/7 production and assuming you don’t completely drown the market by doing it.
this means that these days they are really more collectors items for people with far more isk than they can properly invest. if you have that kinda isk, then sure it makes a decent “savings” account, since they hold their value well and can turn a bit of a profit.
but if your just getting into industry and don’t have hundreds of billions just laying around, don’t worry about trying to get your hands on one, you can still be perfectly competitive even without.