If you don't mind paying a lot for shipping, you can order direct from CNI.
Send them an email and ask for a quote on the specific item you are interested in.
I paid $505 shipped for my GLP-589nm 5mW and ended up with 9-11mW on average.
Yellow is going to be one of the most expensive wavelengths that are produced in portable form so no matter what you are going to pay a pretty penny for one.
Personally, I think that the large size of the Spartan (PGL-III-M) is overkill for a pointer of relatively low power.
When spending that much money, you don't want to settle for something you may get tired of.
I LOVE my GLP. Even though the output is a measly 10mW or so, the color totally rocks and its easy to show people because it doesn't weigh a ton and it fits in a pocket no problem.
I know that if I had purchased a larger PGL-III-M or C, the size/power ratio at 50mW or so would have gotten old and I would hardly ever touch the laser.
But I'm more a fan of pen types anyway.
That said, the 50mW Spartan seems like a good deal. Although someone recently posted about one saying that theirs does not maintain 50mW average. Could be a dud.