You might want to get quotes from Divemaster and Ponyboy.
They both sell the Happ stuff at a considerable discount.
The shipping from Ultimarc gets more reasonable as you buy more.
They have a $12 base price, but they cap your cost on it.
If you order a huge order the shipping is nothing from them.
Bob Robert's shipping has always been very reasonable when I've ordered from him.
I don't think he has any markup on his shipping.
He boxes your order up, weighs it, and then posts it when your check arrives.
Sorry I can't help you on the "which one has higher quality".
All the trackballs I've owned have been Happs, and I've always been completely satisfied with them, so I haven't ever ordered one from Ultimarc.
That said, everything that I HAVE ordered from Ultimarc has been top-notch, so I wouldn't expect that you'd be disappointed with his trackballs.