You can study items for blue points in the Study Table bellow the church. Such items will net about 1.200 blue points if you do all graveyard stone/marble fences and gravestones.
After that, if you still need blue points, the best way is to make glass in 1 furnace, and then turn the glass into conical flasks, and from them onto advanced conical flasks.
Let it run with whatever amount you want and then come back again to get the points. Not the fastest way but for sure the cheapest one, considering that you only need fuel for the furnace and river sand + water for the rest of the items.