Our stay with Ally's parents was fantastic. It is easy to find if you pay attention to the road name, building, and apartment number: we took a taxi to the Prince Villa, and saw building 48, then rang the bell for 101. The steps are steep, but the garden is beautiful!
Our hosts laid out a generous breakfast of fruit, fried eggs, coffee/tea, peanut butter, and toast each morning, and they were welcoming and pleasant to talk with when our schedules coincided. They also gave us good advice for places to eat and things to do, and were responsive to our needs. They were sweet to our 10-month-old son, and didn't seem to be troubled by his inevitable crying.
Their furnishings are beautiful and the common areas spacious, and the bathroom had both a shower AND a tub! The view from the living room is breathtaking in the morning. The room we stayed in didn't have aircon in it, but their main unit was next door in the kitchen and they had placed a good fan in the room. We stayed at the end of July, so it got a little muggy, but it didn't interfere with our sleep as long as we kept the fan on and clothes off.
It was not a far walk to and from Jungdong metro station and Haeundae Beach, and there are eating places to suit many palates (from McDonald's on up) within 20 minutes' walk. Most things are at least a 5-10 minute walk, but despite the hilliness of the area, it's quite pleasant to stroll around in the greenery on Dalmaji-gil. (I managed to catch an offshore fireworks show while walking down to the GS for some late snacks!) But it's only a 3,000 won cab ride from Gunam-ro (the drag in the middle of Haeundae Beach) if you're feeling tired.
All in all, I feel that the price was more than fair for the amenities they provided. It was a fantastic find!