I really wonder whether tearing it down would be much cheaper than that. It has to be, what, a thousand tons of steel? That's at least fifty truck loads easily running at a couple grand each, just to get the readily demolished and disassembled coaster away from the park. Then the labour cost of dismantling the thing, loading the scrap onto the trucks, possibly digging the footers out, disposing of those too, and the fact that the park will have one ride less in its lineup. If a couple hundred thousand were put into a new chassis, at least the coaster would have value as an asset. Putting the same sum into clearing the space leaves them only with the asset of open space, which doesn't quite pull in guests to the same degree. And I doubt its value as scrap would be nearly enough to foot the bill for its removal.