Tell us what lvl do you have and also how many cupons did you saved at this moment. If you are under lvl 80 naruto sage will be a good choice if you also have a gaara, iruka, killer B or gaara the kazekage. If you buy him in sage treasure is around 5k cupons but minato is like 15k. Also you can get fragments for him in events to be even cheaper when you buy him in sage. For example there are fragments to be reedem with points in sakura's gift event. Good luck ^/_\^

just know these things:

1) there are events where is sure to piece jonin minato fragments 1 by 1, so if you invest on him you are sure to recruit him

2) during the past 12 months hokage minato appeared only as the top prize in wheels like this one. This means is not sure at all that you'll be able to get him. That said could be you are lucky and you get him out of 10 rolls or that you are unlucky and you don't get him out of wasting 30k+ ingots.

3) naruto sage mode in china is in shops (i wonder when we will get him there...), and is 90%+ sure that you get him out of free draws in sage treasure within 1 year of free pulls.

You can get sage naruto in the sage treasure so you don't have to spend coupons. Hokage minato rarely shows up in events but is most of the time can be purchased via ignots, which means you can't piece him with coupons. He does appear in RNG events but he isn't guaranteed after using coupons/ignots. Jonin minato can be pieced over time as he appears in several events where you can buy or get free frags over time. If you think you are lucky, go for hokage minato but if you want a guarantee, then jonin minato.

Thank you guys, really appreciate that ;p

you are welcome