I used to use bitdeer quite a bit but they way the contracts are worded they almost ALWAYS win and you almost always lose.  Don't do it other than if you want to play around and watch their figures. 

My last decent purchase was 12 months ago buying s19pro for about .2 btc. It finally ROI'ed in BTC terms after mining for 12 months but that includes the Chinese drop which really really helped.  And this is with what they said <6ct power and no fees. Now power is 7.5c and every plan has extra fees and difficulty is really taking a shit on the returns.

I doubt any of their current plans will ROI unless coins moon and in that case it will always be better to buy btc directly.