Ok, $100.000 post is not that cheap :) If you go with the simplest method, I'd say you first need to understand how much you would need and how much he is will

Ok, $100.000 post is not that cheap :) If you go with the simplest method, I'd say you first need to understand how much you would need and how much he is willing to put in the company and then set somewhere between 10 and 30% for him depending on his day-to-day involvement in the company (which needs to be written down in a contract, of course). But there is way more information needed to give you sound advice here, and still with all the info I wouldn't be the best one to ask. Probably someone from India would be better.