I was able to find a NEW never used Beattie for my ETRSi on fleabay. It brightens the view by 2 to 3 fstops. Landed it for $60.00 + 6.00 shipping.
Simply at the right place at the right time.

Keep an eye for KEH.com They sometimes will have a brightscreen for reasonable price. Their minimum shipping to Canada ($56.00) is too high for my blood though. If you're in the US, expect way better shipping prices.

Good luck.