From previous posts on this board, you're probably stuck for a replacement... But here's an idea.
If it's only cracked, your local B and amp;Q sells a special kind of superglue for repairing cracks in glass. It's like water in consistency, so easily flows into the crack. And it sets in UV light. So you apply it in a darkened room, then put the glass item out in the sun for 15 mins and it sets.
Lo and behold - the crack disappears!
It costs about £8 for a tiny tube, but you don't need much. I've used it to repair glass candlesticks and you can't see the join.