The Meaning of Life, the Universe, and Everything.
If you are able to host your own server, whether you have to pay for it or you have a really good PC and you can do it from there, don't go for realms.
It's laggy, pricey (You can get same performance for less money with external server hosting) and you don't have any control on griefers and thiefes as you cannont check the server logs, and this is the worst part, 100% of the realms where i played got ruined by griefers and thieves, and they never got busted.
Obviously they wouldn't try to grief in a server where the owner can check the logs because they would get busted right away so all the worst player go to realms.
Now you could be very lucky and play for a long time without a problem, and all it would take is one of your old members to get bored and start making a mess, and all you can do is guess, eventually everyone will accuse everyone else.
Realm is good only if it is your only option as you have 0 knowledge of how to host a server, and even than I strongly recommend you you learn how to instead of getting a realm.
If you're talking about singleplayer, you can always try using a program like LogMeIn Hamachi. Your friends can use hamachi to connect to your computer from theirs, which means that after you do this, all you have to do in Minecraft is Open to Lan.