It'll probably take some time to do the hard disk since they have to dismantle the iBook to access the hard disk. I took about 5 hours to dismantle and put my iBook back together after upgrading my harddisk. A qualified technician could probably do it in 3 hours, but that's not much better. Most shops in the UK charge about £100 to upgrade the harddisk, and I found out why after much toil and sweat.
Cat probably got his powerbook within half an hour because they already had powerbooks with the fitted harddisks. All they needed to do was to fit the RAM, bluetooth, and such.