USCIS is not always consistent in their rulings and policies, but if you want to operate your own regional center, it all depends. If you're looking to obtain multiple projects or just associate your current project with an existing regional center, consulting with and retaining an experienced EB5 attorney (like the attorneys at our law firm) can help you develop an approvable strategy.
To answer the question actually asked: No, definitely not, you may not under any circumstances "sell" your Regional Center. The law is clear on this. ONLY the Secretary of Homeland Security may designate a Regional Center and she has delegated that job to her employees at USCIS. No statute, regulation, administrative or judicial precedent has EVER contemplated that some Regional Center sponsor/principal would EVER be allowed to bestow Regional Center Designation upon anyone under any circumstances. The best you can hope to do is work out arrangements with local project developers to become affiliated with your Regional Center for a fee. Such fee should cover the RC's expenses in overseeing EB-5 compliance for I-924A and I-829 purposes plus a healthy profit. There is nothing wrong with that, many do it and have been for years.
Our Law Firm has a client who will be interested in buying your Regional Center in Florida under the right circumstances. If there is a change in ownership of a Regional Center you will need to file an I-924 application for USCIS approval. However, while the USCIS is processing the I-924 which could be very lengthy, there are legal ways to still operate the Regional Center until the I-924 is approved.