I recently did the same research when I was thinking about replacing my Hero 3+ Black with a Session 5. I ended up going with the Runcam Split for now but what I found is that it's best to just get a new Session 5 from whichever authorized GoPro dealer that has it cheapest and then buy this SquareTrade 3-year accidental damage plan. SquareTrade is widely regarded as the best warranty company and they'll either send you a new camera or write you a check for the full amount you paid if that model is no longer available. They won't hassle you and they won't try to replace it with a different camera that might be a lesser model. Plus there's zero deductible on the camera plans.

I'm getting that same plan for my Runcam Split once it arrives. Can't beat $12 for 3 years of accidental damage coverage.