I was just looking at the $30 "on sale" cable that was just components on the end of a few feet of cable. I haven't compared the Bananas side by side, but they looked close sans shroud. The cable could be off-the-roll SO. Your project was definitely a bargain.
I bought four of these banana plugs for $4.99 each (plus $9 shipping). It doesn't leave you much for solder or wire!
The reason I bought the plugs is I wanted about 3' of wire on each generator, so I could run the generators in the corners of my truck box.
05 Ford F-350 Lariat CC 4X4 PSD DRW Line X Retrax
02 Montana Big Sky 3295 RK (2) Honda EU2000is
When my grown kids were inspecting our new fifth wheel, one asked why we bought a trailer that sleeps 4. My reply was that we couldn't find one that sleeps 2!