BA cost/refresh and MPR/VPR (in General)

What are the relationships supposed to be?

Takes a little digging, but the Wiki holds all the answers. : )

When you are below about 2.5% of the top VPR, you gain 10 BA per 10 minutes.
When you are between about 2.5% and about 15% of the top VPR, you gain 9 BA per 10 minutes.
When you are between about 15% and 45% of the top VPR, you gain 8 BA per 10 minutes.
When you are above 45% of the top VPR, you gain 7 BA per 10 minutes.

When getting 10 BA per 10 minutes, you will get 720 BA to be available per day that you can buy.
When getting 9 BA per 10 minutes, you will get 648 BA you can buy, which still is 12 hours worth of BA, and 90% of 720.
When getting 8 BA per 10 minutes, you will get 576 BA you can buy.
When getting 7 BA per 10 minutes, you will get 503 BA you can buy. (However, this is actually 1 less than 70% of 720, which would be 504!)

Either the wiki is wrong or something has gone awry as my BA costs have dropped by about 100 each and my refresh is 8 now (7 before) after leaving some of my xp untrained.

the wiki isn't talking about BA costs, just maximum amounts of buying...

your BA cost increases as you go up in refreshes, more than by just 1, by 100 or so. you've dropped back, so it also dropped.

I understand that. My point is if it goes on VPR then it should not have changed.

BA rate also depends on VPR/MPR of top character. If that increases faster than yours, then you can drop in BA rate.

Yes that is a possibility, however I trained some more xp after the initial post and now BA cost is up by 97 leading me to believe it is going on mpr not vpr.

I assumed VPR only came into account for rewards purposes and that it was still only MPR that determined BA refresh and cost/amount to buy.