Ok. So it cost you $127 to get 27 emails. Before you ask HN (is this good enough), you should ask these 27 people if they will in fact buy. Then you will have a

Ok. So it cost you $127 to get 27 emails. Before you ask HN (is this good enough), you should ask these 27 people if they will in fact buy. Then you will have a sense if there is a market. Now it is pure conjecture. Be bold and ask. If you get mixed responses, ask them if you could interview them. Then pivot as necessary and iterate. Only your customers can tell you if the idea is good enough. You want their 'yes, I will buy" and not Adword stats to tell you if you should build or not. Best of luck