Just took a pass through the light bulb bar looking to get one Sentinel, mostly just to fill in the one spot left where I have all of those type of things placed, and have come to the conclusion (albeit early) that it isn't even worth going for the daily specials in this event. Go for the HOH upgrades, and/or whatever other prizes might appeal to you, and keep the mindset that you're going to get very few, if any of the daily specials.
Beyond that I'll just save most of what I get for the last shot at getting a fully leveled Asylum, and forget about going for two. It's a shame too, I pretty much really like every other element of the event, they just decided to make the best item a blatant money grab. I have no problem whatsoever spending money for things that I think are worth it, but you can bet that I won't continue to throw money at something that clearly isn't.