I think is best gauge is to get more than 60% itm Bottom or 50% itm mid. wheneer u wins a profit to cover the next buy in, is good enough...
You're way off here^^
ITM is something that is much easier to give a general estimation about (you can check out a bunch of the winning MTT players online, and from a very large sample size get good picture of what an avg. itm is). The top (higher buyin) MTT players online are I.T.M. 9%-11% (more towards 9).
As far as ROI goes.... it depends upon what type of games you're referring to. For MTTs it varies greatly.... you'll see between 20 - 100+% in some fo the top MTT players.
For Sng's it's easier to give a general figure.....
Generally speaking, these days in higher buyin SNG's ($100& up), good players ROI is only round +2-3%
In mid-stakes.... 4-10%
low stakes 10-25%
.... this is for 9-plyr sngs
The good poker players who are regs. in the 45's will often have a much higher ROI, +15-+25% range ($25-$75 buyins).
Not sure what it'd be for lowstakes..... although there are some who will regularly hammer away at the $3 & $6 90's and do well.