I'm gonna aim for two myself I think, perhaps three, but definitely two as I love this ship... It's to-scale (depending on your POV of the models from the film and other materials on TIE's) and is really a nice ship...
The price is gonna be what determines how many I can buy though ultimately. I never lucked into clearanced Target TIE's and only got two so this one I'm hoping is more abundant and (more importantly) cheaper. For $30 I'd buy 3.
As far as the deco goes, it's a nice film accurate grey instead of white so I'm perfectly happy with that. The Kenner TIE and X-Wing from 78 were never accurate in color so I don't prefer nods to a bygone time... Accuracy is more important to me there. The light grey paintjob isn't my favorite deco of the ship (I prefer the later blue-grey hulls) but still this means you need at least TWO to flank a (hopefully) grey Vader's TIE that gets out at some point.