The most likely answer is no, it would not be profitable to produce more widgets at the current demand. Since it takes the sale of 500 widgets to break even and demand is only at 400 widgets for $30, such a huge increase would far outway the demand.
However, there is some information that is missing from the question that would inform a more thorough answer. Could demand be raised through any form of an advertising campaign or other means? Is there a cost for establishing a new production line? Would production expenses per widget decrease if more were being produced based on raw material and labor costs?
If demand could be increased without dropping the sales price much and if expansion costs were relatively modest, then it might just be profitable to add a new production line. Without knowing this, it is impossible to tell for sure. Given the information provided though, it is safe to assume that adding a new line would not be a good idea.