Gold coated brass speaker spades

It can matter on some systems.  Solid copper is preferable IME.

Brass??? No. Who is the manufacturer? No reason to keep it a secret.  Plenty of other good cable manufacturers out there. 

"some very nice sounding speaker cables"

This is what matters.

It all comes down to budget- whether the manufacturer feels it is worth it to spend another $100 to construct those cables with better sounding copper connectors, or to leave the cables $100 cheaper and pass the savings on to the consumer, make the price more attractive, in the hopes that more of them will sell.

Honda doesn’t automatically supply $3000 of real leather seats and $2000 18" alloy wheels on a base model $25,000 Honda Civic and make the price $30,000 because it may make the car 1% "more preferred". Half of the people don’t notice, don’t care, and would rather save the $5000.

Some manufacturers, maybe the same one who made the cable you are listening to, design and build cost no object cables, with no expense spared, and of course these cost many thousands more, and would address the last several percent of increased performance, including rhodium/gold coated solid high purity copper connectors.

Question though: have you addressed this in regards to all other aspects of your system? All your other cables connectors are gold/rhodium coated solid copper, including your outlet? Then no, it may not matter.

There are no set rules on this sort of thing.  There are many good sounding and bad sounding examples of all sort of connectors and the binding posts.  A speaker builder in my area who makes custom amps and speakers, some ultra expensive, looks for some very old (and cheap looking) binding posts that are made, I believe, of brass.  They turn out to be not that cheap because the community of small builders know about them and bid up the price.  He has some customers insist on better looking binding posts, in which case he uses the likes of WBT silver binding posts.