I had a similar gouge in the glass on my 125g and it has been fine for almost 4 years i think it is....I did however fill the crack with windshield repair 2 part epoxy. I let it cure so that it pretty much filled in the hole and made it less pointy.
Not sure I would say sure, go ahead and get it, no worries it will be fine, I got my entire 125g setup for $100 so it was worth it. But you can most likely find a comparable tank without the crack.