When visiting Busan, Toyoko Inn Busan Haeundae is a great choice to consider. Guests will have free perks like breakfast, WiFi, and wired Internet. There's a bar/lounge, and rooms offer refrigerators and slippers.
Pros: I had a deep sleep after work.
Cons: the place is small but it didn't matter to my business trip
Pros: Location and cost are great
Cons: 4pm checkin is pretty late. 10am checkout is too early. You should allow people to checkin if the rooms are ready.