I did not like the price either, but they are machined from solid aluminium.
The Aluminia filters are for Feb 2004 on models, post 2004 the scope needs to go back to Leupold to have the threads altered/exchanged.
I have the Aluminia basic kit without the additional yellow filter $32. Having tried the two filters in various lighting conditions coupled to the optimizer, it does what it says on the box. I liked the definition of the optimiser (OP) coupled together with the BZ (bronze) in all lighting conditions, especially in the open and in woodland. It does however give a darker image, but more detail can be seen, weird but you get used to it. As a guide looking at tree bark with the BZ filter handheld in front of your eye, more detail and definition is revealed, acknowledged with other people. Quite pricey and may or may not be worth it plus the scope lenses are sealed and protected by using them- easier and cheaper to replace the filters.
Havent tried the Raincote but should work like Bausch&Lomb/Bushnell Elite 4200 scopes and the stuff that you wiped over your windscreen 20 years ago- the rain runs off.
The Killflash work very well but cut the light down between 15 and 19%. Very short overall lengh compared to a like for like conventional sunshade. The main advantage is for stalkers as no reflection from the scope is given off.