Quick profitability question

[SayGN]

I feel really stupid for not being able to figure this out on my own, but I'm confused. I play the $22+2 sitngo tournaments on full tilt. I also have 27% rakeback on every dollar of mine they rake in, so I am making an additional 54cents per tournament. Assuming I could play the $25+2 pstars tournaments at exactly the same ROI but without the rakeback, what would my ROI need to be in order for it to be more profitable to play on pstars? The fact that I can't figure out how to do this is driving me crazy because I feel like it should be a pretty simple equation.