On the assumption that a gift card is probably free money from a birthday, etc, I would likely be slightly reckless.
I would think about this Monk - no idea about the quality of the pressing, but that cover.
If you are a Free Jazz fan this Cecil Taylor mp3 DL is obligatory - best deal on Amazon. You won't quite have enough for the cd box set...
To continue w cd boxes - this Getz looks good with the little repro sleeves. And there's a Vol.2 of bossa/samba stuff.
This Alice Coltrane or this Dolphy.
Here's a great Mingus deal on vinyl. NPR review w sample. Yeah, I'd definitely be looking at this.