A $5B long/short hedge fund might get a 50 BP spread between long rates and easy to borrow rates, while a customer at a retail firm might get a 200 to 700 BP spread. A large hedge fund might get a locate for 100,000 shares of a hard to borrow stock at a -25% rate while a small client might not get a locate at all. It can be a big difference.
True. But almost all forwards are tradeable in the options market.