Fine pitch BGAs can't be reliably connected with bargain-basement PCBs. Pay up.
Otherwise, find an alternative device that does have an accessible footprint. Or get the dev kit, I suppose (but, again... pay up?).
Fine BGAs are most often used with HDI (high density interconnect) PCBs, i.e., laser drilled vias between layers, filled flat with copper plate. They're not terribly cheap to prototype, but are certainly workable when you get to the thousands or millions as cellphones do.
Tim