Yup the numbers look about right - at least for GEO4, GEO5 and SEO1.

If you're near the ceiling of GEO4 and SEO1, the promotion to the next higher grade (i.e. GEO5 and SEO2) may not be worth it in the short-run. I think it's actually possible, in the first year of promotion, to receive a lower annual pay compared to the preceding year in the lower sub grade.