"is probably being done better than I can do it" .. probably you answered your own question with this. How are you going to take him on based on one feature if he is better? IMHO, Get going on another idea.
Edit: Just editing to comment on how full of "derp" this comment is. Reading comprehension fail on the original post - sorry! :/
If competitor will take time and will help him sell better then one option if you develop the feature is you could sell it to him if you can't compete