[usrusr]

It's not just cost, it's cost x uncertainty of outcome. A settlement is very tempting from cost x uncertainty alone. But it also has other merits: when the rich, powerful incumbent gives in and settles, the fragile thrifty upstart won't see the slightest chance of winning and either beg the troll for an affordable licence (but they won't get a good offer) or look for a completely different line of business. To the incumbent, the settlement is a fee paid for moat-as-a-service provided by the troll.