First, 8GB ECC sticks are actually a bit under $100... retail. You're not going to buy almost 13,000 sticks of RAM retail, are you?
Second, server motherboards are not limited to a mere 8 slots. 16's are widely available, even 32's can be found at retail, and there are more options out there than what Newegg or whatever you're shopping at has.
Second, server motherboards are not limited to a mere 8 slots. 16's are widely available, even 32's can be found at retail, and there are more options out there than what Newegg or whatever you're shopping at has.