I have preexisting illnesses (sorry can't disclose here as it is privacy) based on what my doctor told me. So I was advised to buy pre existing coverage for travel insurance.
Because my work (covered by office travel insurance) or leisure travels are usually in Asia, I bought the Income PreEx coverage annual plan which is about $800 per year.
It breaks even after about 6 to 7 trips in Asia per year (compared to buying single trip PreEx which is more expensive if you leave the country very often).
So don't be penny wise pound foolish when it comes to travel insurance. What's the point of buying a non PreEx coverage when you can't claim at all.