Not being too familior with writing plays myself besides designing for some new ones at times, I have talked with some of the management of some select theater companies that either take advanage of new playwrites in taking their money to refine their scripts by way of contest or attempt to be a development school of sourts to get funding but not really help the writing effort. Otherwise they intend to use the budding playwrites' material as free stuff to save money on scripts in their own productions. If it all works out, great, if not see ya - bad script not bad company doing or choosing it.
There is lots of "actor workshops" out there where the actor is more a source of revenue or fresh audition to add to the pool of people providing scripts, than goal to help those helping the script writer. There is also lots of business and cash in budding playwrites in either finding scripts and writers to take advantage of or to get funding from them in seeming help for making their script realized.
This being the general caution, there is lots of script help out there, just be cautious about which new works contest or help for it you take part in if it might seem to be less in intent than the specific goal of helping new talent. The above warned about sources for script development might not always be bad, such sources just need to be seen for what their own purpose is for the work than the usefulness of them to you in the end to make a functional and useful relationship.