[jjeaff]

Presumably, the makers of Plavix had an estimate of what they could sell the drug for in the US. It's possible it would not have been a viable investment if they weren't able to sell it for 5x in the US. This never bringing it to market.

[athenot]

No because in order to be reimbursed by the French insurance, they must argue their development costs in order to make their case for pricing at which the government will reimburse the drug. Otherwise it is not covered by insurance (which is rare).

So anything sold oversees is pure profit (minus marketing / lobbying).