I don't know about the costumebase quality, but considering I got my flighsuit for about $20 and they're the real deal, I'd say no.
you got a fully modified suit for $20? or are you saying you got an off the shelf orange flightsuit for $20? if you got a pre-made x wing suit that cheap i'm going to :cry
i spent a LONG time on my first one. i bought 2 coveralls (one for the base, one for fabric to make the pockets and such). ripped open all of the seams, made new pockets, remade the collar, etc... i'd say i spent 12 hours or so sewing on it.
the coveralls were $25 each, so there's 50. i bill out at around $50 an hour for normal work, so that's $600
considering that i paid $50 just for materials to make it myself, i'd say yeah, the suit's worth the $78.
the costumebase one looks like cotton twill to me. it's very similar to the workingclassclothes.com coveralls i bought a few years ago when i did the first one.
i'm not 100% sold on the vest. i don't troop with the rebel legion often, so i'm not super picky like i am with my fett. i think that the costumebase vest is fine if x wing pilots aren't your true love, but if you really want to nail the suit, it should go, if for no other reason than the fabric being cotton and not nylon.