Often times there are very good reasons for those restrictions, especially when pricing for a drug deviates dramatically from actual R&D / operations costs. Take the case of orphan drugs:
Besides runaway pricing, many drugs for which companies are given patents and sole-distribution rights, have already been on the market for decades, just never with proper FDA approval. There are other tax incentives and grants provided as well for reintroducing "new" drugs that were already on the market.