I went to a Comic Book / Sci Fi convention in Milton Keynes last year. I won't bore you with the reasons for my attendance, suffice to say it wasn't one of the highlights of my year, ranking just below back pain and watching Aston Villa for entertainment value.
Anyway, at this convention, Gillian Anderson was signing autographs. Pretty much all day, at £30 a pop - no photo's. You wanted a photo, you had to queue again and pay another £30 or you could buy her official photo for £10 and she'd sign that for you,
Apart from a few comfort breaks, she was there for a whole day and for the whole day there was a queue outside her little booth. We sat and watched the queue a few times and it was moving at a fair pace, she wasn't exactly giving people 20 minutes of 1 on 1 pillow talk. The ticketing system was a simple 3 digit raffle ticket and at the end of the day was in the 700's. We therefore scientifically estimated she'd signed or had photo's about 700 times, plus selling the photo's and merch that she was signing!
Not bad money, I'd love to know what the split was with the organisers. Even at 50 / 50 she must have easily cleared £8 / £9 / £10k for a day's 'work'.
Sylvester Mccoy did less well.