It's only 2000 yuan at most, because it's not that difficult to get an autograph. Howard has been to China many times, and his clothes may be worth some money if they are good. If Howard wears clothes, it is likely to break through the 3000 mark.
In short, if you want to sell for a good price, you must find Howard's diehard fans. It's better to ask questions in Howard's post bar than Taobao.