That is actually a fair to good price for around here. I'm more used to seeing 3 to 4 inchers around here for that price. Never seen one in an LFS for less than $50. At that size, usually closer to $100. I've seen them in RI LFS's for around 20-30, though. Your not too far from there, either...Pick up some RBP's while your there...JK.
$73 for a 6 inch Silver is high in my opinion. Silvers are the most common and easiest to get. I see them @ 10 12 inches and sometimes bigger for about that same price here in southern California.