The event as of this writing is on
day 22 according to this document. From there, there's not a whole lot left. At least, not to me. Your situation may be different.
If you're thoroughly unenthused with the prizes as-is or will-be, you can use the "Re-roll" feature to generate a random (as chosen from the pool of all available prizes of this event) daily prize in an attempt to get something that more closely matches what you want. All you have to do to use it is gain 5 points.
Those points are not subtracted from your total; you simply have to have gained the number of points indicated. The required points reset upon each use of the reroll feature, or when a new daily prize is generated after the indicated timer has run out.
Or you can spend some amount of diamonds if you choose not to or cannot gain those points at that time.
EDIT: While the remaining prizes aren't that great, you could wait until you reach a prize that is closer to what you want than not, then try rerolling then. At least if you get that prize before you're able to reroll, it's not a total loss.