Only 500 Blurays?
My Bluray collection just hit 1000 Blurays. The best way in terms of cost is to use Sony BDP-CX7000ES 400 Disc Bluray Megachangers. I own 3 of these changers, and last year was the best time to buy them. The cost had dropped to $199 (Sony Outlet store) to $700 US. Each Changer has capability to hold up to 20 TB. So, if you compare them to a Server, the cost for the server is too much for Bluray. $2650 for 5 (4TB) drives.
You can still buy these changers on Ebay, but hard to find.
I also own a server with 16 (2TB Hitachi), but is on Areca Raid 6. It was primary designed to handle my DVD and CD collection. I am upgrading to a new Asus Thunderbolt motherboard, so it allow me more space in the future.
Actually, my Sever is small to this other forum. The owner of the forum has (4) 4U Rackmounts with 24 Drives per Rackmount. He started the collection in 2008, but now is over 100TB. He has all Bluray movies too.