Sky9
I don't think that's quite correct.
There have been a few threads broadly covering this topic.
To recap:-
Take Off Run Available (TORA) is the actual physical length of the useable runway.
Accelerate-Stop Distance Available (ASDA) is the TORA plus stopway.
Stopway is a surface on which the a/c can be stopped after an RTO. The surface may be damaged by the weight of the a/c.
Take Off Distance Available (TODA) is the TORA plus clearway.
Clearway is an obtacle free surface over which the a/c can fly while achieving screen height. Stopway is clearway. Water beyond the end of the runway can be used as clearway. There are certification limits on how much length of clearway can be used.
akerosid,
The short answer is yes, it could be quite cost effective as it's not full load bearing pavement required for stopway.