For General Information, page-2760

Hi Mr Perry,
A PRV can be transferred once, to another pharmaceutical company for the use of neglected diseases and rare pediatric diseases. The rights to use it are transferrable.

A company may have plenty of cash when they get marketing approval for a product from the FDA, so for them, it may be more beneficial to use it themselves.
If they can obtain a profit of more than $150m in 6 months then it may be worth retaining and using it themselves.
If their profit was under $100m in 6 months then it is possibly beneficial to sell it.
(It can also be relative if they have a second, or more, drug in their pipeline or platform which could be used later)
Another company may have basically no cash, no funds available to produce and manufacture for marketing, or a variety of other aspects. So for them, $100m+ could be very useful to get the product to market without having to borrow, partner, license, or sell to a bigger company.
So in essence it can boil down to whether you have much cash at hand to meet the requirements to proceed to market.