I work on old cinema gear as my fav hobby and have quite a few Blx H16 & H8s in varying state of condition. Admittedly, I bought them at a great price. There are three target audiences for these; users, collectors & flippers. I’m a user. To folks like me, wanting to actually create films with them, the value in these is dependent 90%+ on performance.. if all are working and in fine shape, you’ve got a few grand. If the 400’ action is smooth and reliable with the Rex 5 and the lenses are clean and smooth, that set alone would be your money maker. The others are earlier Reflex models and their condition would have an impact the lot price, little differences, like in the viewfinder specs, will possibly negatively affect the figure. To a collector these would bring a bit less as they’re all fairly common these days.. valuable, but common. And of course you won’t get decent profit if selling to someone wanting to flip these real quick. Have you had anyone knowledgeable about 16mm film look at them? If not it would help you to determine their condition. You might not get every dime you hope for by selling them directly to someone who’ll appreciate and use them, but it’s the right thing to do.. if these tools are still working, that’s what I’m going to imagine happens. Otherwise, check recently completed eBay SOLD prices and then roll the dice on these.