Gotta make it quick as baby screaming in the background but just my 2cents from a fellow forum member and someone who's been through this whole fiasco personally - buy a T4B from Drip / Kenetek / whoever, take out the guts and call it a day.
Astonics is LSI. The $82 a pop is their way of saying "please go away, we know what you want this for and we don't want to be bothered if you're not a multi-billion dollar aircraft manuafacturer, I know, I've tried, in very large quantity request using reputable credentials, I got better than $82, but not that drastically better a price"
I don't want to start the T4B argument on Peter's thread but there's more to a good sounding T4B than slapping any 2 photoresistors on a LSI panel. Sure, it'll work....maybe not so great though. There's a lot of time and labor involved, Drip and Kenetek are proof of that. Not trying to discourage you guys but reality is in the end you might ended up costing yourselves more money than just buying the sure thing.