What should I do with my 2006 Macbook?

I would invest in a MacBook Air. The older you MacBook gets, the more you fork out in repair costs. MacBook Airs are built to last longer, with their Flash storage and all that, and up to 8GB RAM and 512GB storage.

As for selling existing one, how much 'ya want for it? 😁 😁 Really, I would simply start out by seeing what the going rate is on eBay, Amazon, etc. and pick one of those to sell it on. There are some sites specifically for selling Macs, but chances are you would get less for it.

If it works, why replace it? Just because Apple and others bring out new things doesn't mean you have to buy them (sorry Apple!). I am still running a G4 with Tiger. Oh, I am missing out on a few things but I also only have an average computer spending of $200 per year for the past 20 years. That's for everything, hardware and software.

On the hard drive space, that is the penalty of having a notebook style computer. People want smaller and smaller hardware but software is getting bloated and multimedia more in demand. Review what you have on your drive. I did that and found that I don't look at photos every day (or even every month), nor videos, nor even certain music. I stick it on bare archive drives and use a drive dock - http://eshop.macsales.com/shop/NewerTech/Voyager/Hard_Drive_Dock When I want to look at a photo, or read a paper I wrote back in 2002, I can get to it in a few minutes.

Craigslist. I much prefer to buy this kind of thing locally where I can have a look at it, test it.

Insert the Install Disk 1 to restore to factory settings.

If you back up your data files, delete the the rest, then re-insall the stuff you deleted and put back on the stuff you backed up, you'll be back where you started. 🙂 Oh, you may clear up a few MB in unnecessary old preferences files, but it won't really make a dent unless you had some unnoticed currupt cache files or error logs. Of course, if in doing all this you also review what you copy back on, that might clear up a bit of space. Do you use Garageband?

These days it's the thousands of photos and music files, and even just a few 500 MB video files, that really gobble up space.