So am I reading this right? The benefits of trying to go from O-4 IRR to SELRES and hustle to O-5 generally outweigh the costs?
Depends on how much your retirement means to you. An O-4 reserve point is generally worth $6.37, and O-5 reserve point is close to $7.52. Add in the fact that O-4's are done at 20 years of commissioned service and O-5's can go to 28 and thus accumulate more points, there can be a substantial difference in retirement income.
(for reference, 7200 points equates to a 20 year retirement, i.e. 50%)