I have an old original GBA, it's a white one.....and I got it for free!
My bro got it from a dude at his work who was cleaning out his garage and found it in a box. When the dude tried it, it didn't work, so he gave it to my brother and told him to do whatever he wants with it.
My brother has worked in electronics for many years, so he wasn't afraid to take it apart. He's not into videogames or the systems, but he appreciates their worth as a significant piece of electronics.
The guts to the thing were quite nasty. It looked like someone used it as an air filter or something. It was caked with dust and dirt. Ever see a neglected CPU fan in a PC? That's what it looked like. My bro cleaned it out completely. We put some fresh batteries in it, popped in one of my GBA games and it played it fine
We also got an old game with it.....can't rem if it was GB or GBC (I could go look, but I'm too lazy for that).....but it was called Crash Test Dummies. My bro cleaned that out too. It looked like someone shoved it into the dirt.....contacts first. Well, it's clean now and it works too. It's not a very good game, IMO......but it works.
Since my bro isn't into such things, he gave it to me.
The GBA has kind of a nasty scratch across the facing, but you can still see the screen ok. All buttons and switches work perfectly. The battery door is not original....it's purple when the GBA is all white, but it holds the batteries fine, so meh. Free is good.
I already had a GBA SP (old side-lit style, blue) at that time, but I've since sold it when I got my first DS phat within a month of its launch. I sold the DS phat when I got my Black DSlite the week they released black and pink in America. My old DS phat is still working perfectly for my niece, who is the new owner. I still have that free GBA to this day.....and it still works. It's collecting quite a bit of dust right now, but I have it. I'm thinking of buying a separate slot2 card for it and have it as the "throne" unit.
I mostly play GBA games through my SCminiSD on the DSlite now, but I still play GBA games a lot.