You missed the time for investing in BXPW. Just wait for after the weekend and the price of potions (like brews, pray pots) and things like blue d'hide bodies will drop below the normal price.
If you're looking to invest, you'll have to wait until the second-third day of BXP weekend and just start buying things up for dirt cheap. Then when they return to normal price, sell them again.
I remember last BXP weekend Grenwall spikes crashed like a mofo.