That's what they sold for.
I know the O.S.T (Outside terminal) receivers go for quite a bit of money. I see 4. I've seen them go for $200+ each. Probably not a bad price, you could re-sell them for much more than that by selling them individually. I count 22 total. Or you could re-purpose them into a unique chess set.
I paid $80.00 for a badly cracked Pony receiver.
Jim H. is right on. They are not cheap. I can see two that look fairly good condition. So that could cover most of the $400.00 plus selling price.
D/P
A couple of long poles and several WE receivers that sell around $30-40 each
WE 143 and SC brass bottom receivers