The Humber Sports is more or less exactly the same bike as the Raleigh LTD-3.

The more expensive Raleigh-made three speeds are a lot like the less expensive ones, and from what I can see of the bike in the photos, you have one of the latter. To confuse the matter, there are also chronological variations. So, in view of that, and looking for features that distinguish high-end Raleigh three speeds:

A Raleigh Sports would have Raleigh pattern rims, sometimes called "Westrick." The bike in the photo has the regular, less expensive (but also lighter, and in my opinion preferable) Dunlop rims.

The more expensive Humbers have a Humber pattern chain ring, which looks like this:

The bike in the photo, sadly, doesn't.

A Raleigh Sports would have a Brooks B72 saddle. The one on the photo has a cheap mattress saddle (probably a Brooks).

Cheaper and later bikes have the gear cable running in a housing all the way to the chain stay; the bike in the photo has it run over a pulley, which is preferable.

The bike in the photo has a grip shifter. Kinda cool but not as reliable as the trigger.

As for your assessment of the value/price, I tend to agree. But we have another forum for that.