Originally Posted by Tropwen
Well I definitely consider myself a serious player I have two toddlers so I can only fit a good MTT and maybe a SnG or two if the day wasn't that eventful into my grind
Most wouldn't consider this ^ to be 'serious'. Serious SNG grinders would likely consider 50games/day to be recreational.
And its not that I'm in a hurry to move up I am wondering when it would be most profitable for me and I'd consider myself a fairly good STT/MTTist averaging a top 28% finishing
As you move up in buyin levels the players (on average) tend to be better (especially the regulars). It is more difficult to run with a high ROI at higher buyin levels than it would be in micro &/or low buyin levels.
As others have mentioned, ~50 buyins for SNG's, & at least 100 for MTT's (< more if you're playing larger field tourneys regularly).
If you want to discover what would be most profitable for you 'it depends'.