I follow the little trailers rabidly. It's a fair ebay price but I wouldn't have gone that high. It didn't have anything special to grab me.
This is sheer conjecture, but I think the little, pre-'64 trailers have a certain buyer, like me, who isn't concerned about anything except uniqueness and, to a certain extent, manageability.
We don't care about axles or how much money we'll have to sink into it & we're confident that down the line we'll have a valuable piece of merchandise no matter what.
Here's what I thought when looking at the listing:
On the plus side, the body is in good shape & it has lots of original bits.
On the negative, that's a strange layout & the inside looks pretty ratty.
For comparison, here's a similar one that just sold:
(listing #4571203902 if the link doesn't work)
To my mind, the '59 has everything going for it & the sale price was only $48 more.