Here are somewhat incomplete ranges of the NGR and NOP high values from the Beginner's Collection.
The NGR range is missing the 25c, 10p and 20p values. I find the 25cNGR to be scarcer than any of the other values-including the 5 pesos!
This is a common stamp, except for the light shade example shown here.
The 40cNGR is uncommon, even more so in the lighter shade.
The 50cNGR is also uncommon.
The 1pNGR is fairly common.
Most 2pNGR stamps were printed on grayish paper, these two rare specimens were printed on higher quality white paper.
A rare stamp, yet overvalued in the Scott catalogue.
The NOP range is missing the 40c, 2p, 5p, and 10p vaues.