Is a high end memory card worth splashing put for?

... If you're broke? I recently used all my photography money on a Canon 5d mk IV and a few expensive objectives (so excited!!!), and now I'm essentially broke. I don't plan on shooting much video, but I am looking to shoot some sporting events. 90% of what I'll be shooting will be, erhhh, calm settings where 7fps shooting won't be required. Since I'm wanting to use two memory cards, buying two high end memory cards is a luxury I can't really afford (for now) unless it's absolutely necessary. What do you think? Hands on experience is very welcome.EDIT: The two cards I'm wavering between is either a cheap-ish UHS-I card with around 100 mb/s writing speed at roughly 40 euros, or an expensive UHS-II 300mb/s card at a commanding 170-ish euro. via /r/photography https://ift.tt/2Ls7FnO