...long long while ago and cost about £100-£150 (not Virgin). Wasn't that interesting though - a bit dull.
Unless there's a good reason, I'd get your friend a trial lesson in a Microlight, much much more fun.
I definitely recommend it, I went on one in Devon about 4 years ago. It was a christmas present, so I'm not sure what it cost.
Obviously it's very weather & wind dependent, so you might have your flight cancelled more than once before you actually get to go up. We were lucky and were able to do it first time.
It's great fun just slowly drifting across the countryside. Gives you a new perspective on it. We did it in the evening, so the long shadows gave a wonderful sense of depth. We spooked a flock of sheep or two and saw some foxes as I recall.
We eventually landed on our backs in a field full of stubble, which was quite exiting. We also had to help unroll the ballon envelope and roll it back up afterwards. It's all part of the experience.
Tip: Wear a hat, the gas burners throw off some serious heat downwards as well as up.
Bought one for SWMBO's 21st, could only pay for her's are it was expensive and I didn't earn much back then, I took the photo's as they took part in getting the balloon ready then gave her the cam to take some pics up there, she enjoyed it but obviously said "wished you'd been there"
It was with Virgin but they don't do Scotland so it was another company that done it on their behalf still with the red balloon, I actually thought they were more personal, the staff asked a lot of questions at the end and handed out champagne.