Right. Have you ever done this? Try downloading 219 MS security updates plus one or more service packs and rebooting about 12 times. This is AFTER you install windows the first time. And hunt down all the drivers you need. And install them one at a time and reboot in between.
$80 is NOT getting ripped and is actually a pretty fair deal. Many places would charge you a lot more than that. What is your time worth? Do you have 5 hours to blow babysitting your old computer while it downloads/reboots? In case you don't know it already, sometimes with an old computer its actually more efficient to just buy a new one. Why blow $200 reloading an old piece of **** when you can get a brand new one for $400 that is 3x faster.
I wish my friends that ask me to fix their computers would read this. I have no problem doing it and I don't expect anything from them but when they offer to buy me a 12 pack or a beer at the bar for saving them $100 or more, it's insulting. Just say thanks and I owe you one. The next time I'm working on my house, offer to help.