Q: I need the opinion of an expert....original macbook air rebuild?

SSD and Display assy.       Your talking about replacement cost being 60%  of a NEW unit.

($420 + $220 [depending on SSD size])

worth it, no

It doesnt contain a HD, rather a SSD, why do you think it needs same? missing?

sell it off for parts and buy a new one.

Also you didnt say how OLD an Air it is,...2010, 2011 model, absolutely not worth it

Yes, you can get a used LCD Air display as a parts extraction from another dead machine. $100 is rather cheap however, verify it works before you buy it first.

Yes, the Air has a SSD inside, ....not a HD.   And there are no "cheap" SSD options.

older Air uses micro SATA SSD, new Air uses PCIe

what year model, what screen size? 11 or 13"  what SSD size?

odd pixelation indicates possible faulty LOGIC BOARD, not necessarily a bad monitor, in which case, youd be glad you got it for free.

picture of monitor faulty image?

I would say great choice for a first mac,...but the condition is, ehh 

Good, external monitor is fine, logic ok from indications.

2008 a nice older one,...if you can fix same with a mere $100 used LCD, then yes, even I would do it.

Hey, I fixed a 2007 Mac Mini for my dad as his "first Mac"   Didnt cost really anything

even though its only got a 500gig HD i upgraded and 2gig max RAM,...

hes so happy with that old machine, he swears its far more reliable than his new computer and faster too.    Which really it about is.

A fixed used Macbook Air is a perfect "get you hooked" Mac to get as a first machine.

Yes, you just mentioned it was a 2008 model, which has a different drive, rather than the SSD on recent model Air.

http://support.apple.com/kb/SP501

Just to use it as a first macbook, 80gig is good enough, my last Air I sold off only had 64gig SSD, and was plenty enough.

OS for 2008 Air procedure:

http://support.apple.com/kb/HT2735