I can't tell for sure, but is that a single comb on this one?
If this is a cockerel I would not use it for breeding at all. If it is a pullet and you don't have any other options, you can use her but be aware of spreading a single comb gene out into the population. So, if you are selling these first ones as pets, make sure her chicks go to pet homes, not into breeding homes. Then as soon as you can, remove her from your breeding pen.
If it is a single comb, best choice is to not use it at all, but... start with what you have but keep good records and be transparent with your buyers. Also, if it is, do you know if any other chicks have the same father and or mother? If any have the same father, they will ALL carry 1 copy of the single comb gene even if you can't see it.