The risk of getting a round trip plane ticket is that you'll never know when there's an emergency across your trip and you have no time to rebook your flight. Then, so you missed your flight and turn it into a waste and you have no choice but to get another ticket and that will cost you double. I had this personal experience when I traveled to somewhere and it's not a good experience that it wasted my money. So, I told myself that the next time I travel, I will no longer book for a round trip ticket. But that's just for me but it can happen to anyone too. I'm just sharing this thinking that I could give you an idea but still the decision is up to you. Have a safe trip!
Depending on the type of emergency, the airlines will often work with you to rearrange your schedule. In some cases it is okay to buy two one-way tickets, but in most cases, roundtrip will save you a significant amount, especially when you purchase your tickets in advance. If you are buying tickets right before the flight, I can see where buying just one way will benefit you. I'm sorry you had a bad experience. I'm sure the stress of the emergency made it even more frustrating if the airlines weren't cooperative.
It really depends whether you book international or domestic (US) because international round trips are cheaper for some tickets and also compulsory for some countries. If you don't have a return portion you may be denied entry, because they need to know you will leave. I've bough round trip tickets that were cheaper than a one way and didn't used the other portion, but also you can pay to change the ticket date too.
Theo is right, sometimes you have to book a round trip ticket. But for the reasons listed in your post it might be best to purchase the extra insurance in case you have to change it. Some search engine companies will help you change your ticket for a small fee (or a fee that would be equal to the cost had you bought the insurance) but others will not. We had to extend a trip once through Expedia just because of a dental problem, and for $200.00 extra we were able to keep everything the same with only a change of the dates. But like I said, it is a risk not to buy the extra option to be able to change your ticket, because when a problem arises you are at the mercies of the ever changing customer policies.
We usually travel on discounted plane tickets and since our travel plans are finalized before then so it is imperative that we get a round trip ticket (for me and my husband). Fortunately, we still have not experienced rebooking our flight, I would hate that. We had 5 trips this year - China, Malaysia, Vietnam, Hongkong (with sidetrip to Macau) and Singapore just last week. From what I know, rebooking a discounted ticket will cost us more, better to buy new tickets.
I've also been in the situation where rebooking fees were more than just buying a new ticket, it's odd how life works out sometimes. Personally I would book with the insurance just to be sure that you will have a ride back. Last minute tickets usually cost quite a bit, so cancelling with insurance would probably be cheaper anyway since they'll work with you on changing the dates.
Fortunately, we haven't really experienced that we have to rebook our flights as well. We are really careful about time and day and also we didn't have any emergencies to attend to. But yes, in such cases, booking a round trip might be wasteful. But for us, for vacations, we really set aside that time for it and so roundtrip flights are cheaper for us.
No one likes to waste money and emergencies do come up, which is a very good reason to purchase travel insurance. I will admit I have never given it a thought until I was on a call talking about what would you do if you got sick while traveling and had to get home to your doctor. What would you do? Travel insurance can help to take care of those types of emergencies, trying to get back to your residence or to your local doctor by ambulance can be very expensive, now that I am more aware of the situation I do believe I am more inclined to purchase the additional insurance next time I travel.
@Lovely Babe I'm sorry you had to undergo such hassles during one of your trips. I guess situations like what happened to you are good reminders to always consider getting travel insurance as what @Pat said. We never know what can happen to us while we're on a trip so it's best to apply for travel insurance. In this way, if emergencies would ever occur during a trip, the cost of re-booking an already scheduled flight would be lesser because of the assistance of your travel insurance.
You know I have never not booked a one way flight. I spend so much time securing the right price I would be worried that when I bought my return flight it would have gone up in price or not be available. Plus I don't want to have to deal with booking a flight while I am away I would much rather have it planned out and ready to go.
It does depend on the airline you are using, I had a problem once with a low budget airline and completely lost the money for the return flight. Some airlines are quite flexible, I changed a Qatar airways flight once for only a little expense. Often the total price for a return flight is cheaper than booking both flights separate, so in that case it is wise to book return flights.
It depends on a lot of things. Frankly, I am always looking for the cheapest refundable tickets. Usually, the cheapest ones are for round trips only. Also, it depends on the airline. I fly for FF miles and for cost effectiveness. Airlines usually handle any schedule changes on my side easily. So, I rarely face such a problem.
Round trips tickets usually save you a significant amount of money. Many times the situation causing the delay will be affecting other airlines also, and it would be difficult for the others to be active whilst your carrier is grounded.