As a guideline for bidding, mah87 could get BTC50 instantly by selling these on the market, and it would cost you BTC55 min to acquire this much XRP on the market.

Thus the pricing for a quick sale should be between 50-55 for this quantity, even though I think mah87 is a bit mad to be selling this much, when it's value is on the rise again and could easily hit BTC65 by the end of the week, or even 80 if one wall goes. It'd take a tremendous volume of XRP which doesn't really exist on the market to move the price below BTC45 for this quantity.