Go for the fruit. It is the best coupons/key value you will get in any event. It will probably help you to get over the 50 or maybe even 200 key rebate checkpoint.

It will also drop a lvl 5 rune, with some luck you will get initiative, or critical/combo which is also nice.

Bottom line, unless you are saving only for a specific ninja or for only refines, go for it.