GTX 1080 FE vs GTX 1080 Ti FE

I will like to hear your advice regarding the cost/benefit relation between the GTX 1080 FE vs GTX 1080 Ti Founders edition. Which one would you buy for a cracking rig?

The GTX 1080 FE has a street price of $750 :

• Base Clock: 1607 MHZ
  
• Boost Clock: 1733 MHz
  
• Memory Clock: 10010 MHz Effective
  
• CUDA Cores: 2560
  
• Memory Detail: 8192MB GDDR5X
  
• Memory Bit Width: 256 Bit
  
• Memory Speed: 0.2ns
  
• Memory Bandwidth: 320 GB/s
  

The GTX 1080 Ti FE has a street price of $1,300 :

• Base Clock: 1480 MHZ
  
• Boost Clock: 1582 MHz
  
• Memory Clock: 11016 MHz Effective
  
• CUDA Cores: 3584
  
• Memory Detail: 11264MB GDDR5X
  
• Memory Bit Width: 352 Bit
  
• Memory Speed: 0.18ns
  
• Memory Bandwidth: 484.4 GB/s
  

Thanks.