As I've mentioned before I'm keeping my eye out for that elusive super cheap projector that I'd be willing to use in situations where it would very probably be destroyed or stolen.   Not that I want any projector to suffer that fate, but even though I've extremely cavalier with $500 and even $2500 projectors I'll generally only do things with them that I have a pretty high expectation of them surviving and being used again.

Perhaps for some people that price point for being able to say "oh well" is higher but for me it's ~$50.   none of the above projectors have hit that mark yet but they are getting close.

I don't really want to dispose of the projectors but I imagine using them in street installations, or party installations where the likelihood of them walking away or just getting smashed is >25%. And based on my experience with occasionally killing a $50 component of a robot I think I can take that.

A month ago I spotted the EyeClops Mini Projector in the store for $100, it seems to be the closest yet, and looks like the price has dropped to $80. 
It's also gotten some good reviews, which I put down to the "price point", not the "features" which are sketchy, not lumen rated and no pixel dimensions.  But it is battery operated which is pretty cool.

The Zoom box that I had my eye on and mentioned in the past seems to have become unavailable without every dropping below the $200 price point.

But just today I spotted a much higher end LED projector for $150. Recertified: 3M MPRO 110 Still not in my target range for price or lumen, but a very nice little package, much smaller than and better Pixel resolution than any of these other toy projectors.

A last mention in the toy projector realm is the Torpedo Entertainment and Game Projector which I have also mentioned before, but it's actually a bit higher priced than last time $100.  Non-LED lamp probably brighter than the LED options if hotter and more power draw.  Though this one can be run off a 12v battery pack.

I have not tried any of these little toys out, they all look fun, but just a little to expensive to pick up without a specific job for them yet.   Though I think I'll be giving one a try sometime soon.

We did some product research on the LED projectors a few years ago, and
what we came up with was that they probably needed to hit the <$100
price point to sell to a wide enough audience.  Also we felt that they
needed to hit >=60 lumen to actually be usable and better than just
looking at your cell phone screen.

none of the projectors here seem to meet those criteria yet actually.