Nobody will give you any particular answers. Start with a high % and negotiate down. I doubt you will get 25%. If they offer you X number of shares, but don't

Nobody will give you any particular answers. Start with a high % and negotiate down. I doubt you will get 25%. If they offer you X number of shares, but don't tell you what % of the total number of shares they represent, don't take it, it's a ripoff.