Good decision. It doesn't matter what the job paid. You DON'T need or want that kind of experience. Later on, if you were look for a job and I was interviewing you and you said you did single engine ferry work over extended non-survivable water, I'd seriously question your judgment. Most light aircraft belong in a BOX when crossing extended overwater segments especially where the water conditions are not survivable. The reason people want to ferry them is because they are cheap screws and want someone else to risk their life.

Exposure suit or no, even if you managed to get into a raft after a ditching, how long do you think you could survive? Assuming that anyone heard your distress signal, how long do you think it would take for someone to find you and pick you up, perhaps in heavy seas? The answer is: They won't and you're dead.

You don't have to jump off a cliff to know it's not good for you. If your life depends on the luck of not getting bad icing and an engine that is owned by someone else staying turning, then I'd say that's unacceptable risk.

Good on ya for figuring that out.