Lol well in that case tehres still a glitch for me, I only had 3 silver prints and I couldn't buy the statue when I had 2 :S
Well, I now think that one unlocks after you challenge every Frontier Brain(or they challenge you), and another when you get a Silver print. That could be it...
You had 2 silver prints, but then you didn't see all five Frontier Brains, only after you got the third print, am I correct?