A lot more people than you'd think spend days feeling uneasy after signing up for a policy. At the moment you sign, everything the agent says sounds right. But once you picture more than 180,000 won leaving your account every single month, the thought creeps in: "Did I just get taken for a ride?" That feeling is especially common if you've had surgery in the past or you're on regular medication, because in those cases the premium tends to jump quite a bit.
The kind of product people usually call "pre-existing-condition insurance" exists for exactly these situations. Unlike ordinary policies that only accept healthy applicants, these lower the bar so that you can still get in even with a chronic illness or a past medical history — and in exchange they charge you more. Looking expensive is, frankly, only natural. The company is taking on more risk. So instead of asking "why is this so expensive," the right question is whether the coverage you're getting is actually worth that price.
There's one thing worth knowing that takes some of the sting out of it. An insurer sets your premium by looking at your medical records from the few years right before you apply, and within that, whether you were "hospitalized" carries quite a lot of weight. The catch is that even a single overnight stay just for testing can get recorded as a hospitalization in the system. Take a test where they have to monitor you through the night while you sleep — you weren't lying there because you were sick, but it still ends up tagged with a hospitalization code. That can be the very thing that pushed your premium up. And honestly, it's a bit galling from where you're sitting: it was a simple test, yet it gets treated like a medical history.
When this happens and you only signed up recently, it's worth contacting the insurer directly to ask about cancelling the application or having it re-reviewed. If you can show — with a medical certificate or a doctor's note — that the stay was for testing rather than treating an illness, there may be room to reconsider the reason for the surcharge. There's no guarantee it gets knocked down, but pushing back once beats just accepting it and moving on. And if the medication you take day to day is something like an allergy pill or a mild psychiatric prescription, getting comparison quotes from other companies is another route worth taking.
In the end, whether a policy is good or not isn't something the price tag alone can answer. The fact that it's non-renewable, so the premium won't climb later, and that you pay for 30 years and stay covered until age 100 — those are clearly real advantages. But whether the conditions you're actually worried about are sufficiently included in that coverage, and whether there's a more sensible alternative under the same terms, is something you owe it to yourself to check one more time. The money going out each month is not small, so if a corner of your mind feels uneasy, don't just let that unease sit there.
What's written here is only general reference. For the answer that fits your exact situation, the most accurate thing is to ask your own insurer or an independent insurance advisory directly.