My experiences lately with my NEW (to me) 20" iMac G4.
1.25 GHZ PPC 1 GB RAM 160 GB HDD
Purchased on eBay in the orginal box for $349.00 delivered.
When the computer arrive it appeared to be in excellent shape. It turned on and operated without any problems. I really purchased as a project, and intended to restore to as NEW as possible. The iMac arrive with the usual specification for the model (born on date 3/2004). Specification were 1.25 GHZ PPC, 1GB RAM 512/slot.
So I purchased some parts to get started (like I said above everything worked).
1. OWC RAM 1GB/slot for a total of 2BG's ($55.98/Free shipping)
2. OWC PRAM battery ($3.99/free shipping)
3. OWC LG internal Optical Drive ($45.99/free shipping)
4. IOGEAR Bluetooth (ver 2.1) Adapter (USB 2.0 Micro) ($13.99/free shipping)
5. Apple Wireless Magic Mouse (had a spare)
6. Apple USB Keyboard (newest) (had a spare)
Before installing the parts I cleaned out the dust and grim (nasty dirty), removed the Fan and cleaned (nasty dirty), I also removed the Thermal Grease and applied new Thermal Grease (used Artic Silver 5 Thermal Compound). I used a powerful vaccum and a air compressor (120 psi), and damp Q-Tips.
On the outter shell and back of monitor I used SoftScrub/Bleach lite scrub and then rinsed with a damp cotton rag (looks brand NEW). Was sure to remove ALL of the SoftScrub.
On the screen I used iKlear and a iKlear cleaning cloth, screen is in MINT condition.
Honestly the computer looks and operates much better than I had anticipated.
I really didn't need to install a new Optical drive in the 20" but it was a cheap upgrade. And so. I have a iMac G4 17" with the same spec's as the 20" iMac so I opted to install the 20" iMac's Optical drive in the 17" iMac. The 17" would only play CD'd and not DVD's.
After putting everything back together I installed Leopard 10.5.6, then upgraded to 10.5.8. I installed Quicktime7.7 for Leopard and iTunes 10.6.3. Installed iLife09 (no iMovie), iWorks09, Superduper (latest), and Disk Warrior 4.4,
I chose not to upgrade the HDD simple because it is working fine and I don't have any critical information stored on it.
My final upgrade would be to install a new FAN but I'll wait on that for a while. Since the Fan operates fine it does have a very, very slight whine meaning the bearings are starting to wear a bit. Probably because of the dirt and grime that was on there from before.
I would like to buy a NEW Fan to install but right now the only option is to buy a Apple Fan (part# 622-6215). I wouldn't mind a non OEM Fan but the little fins on the side of the Fan's walls are a concern for proper air flow.
http://www.welovemacs.com/9226215.html ($69.95 + $4.50 shipping)
Spent to date not including Mouse/Keyboard on my 20" iMac G4 $468.95 ($349 iMac, $119.95 parts)