You can use them/sellem/arcade em at 20, 30, 50 70 or whatever repair percentage. It only impacts their value a bit.Note about arcade and bots - it seems to me that intended idea was to give you additional source of income etc but you cant do anything with bot until your repair it and as i understand you need a lot of repair skill in your character to do that, and its kinda strange that you have to grind that stat a lot before you actually can do somthing with bots since for me they already trained and all but i cant use them cause i stuck at 70% repair value
A good bot is worth millions also at 50%.
Furthermore after a handful of repairs(literally a few game days) your skill is up to max already.
If you're clever, you could also invest in arcade solutions, send em un repaired to the arcade and they are upped to 100% every day...