It’s not so much the price for level 5 EB as it is the time it takes to unlock rep, farm credits, and then the limited season.
I broke down the pricing and found it would still be very lucrative to purchase a level 5 EB. With only 30 days of 5% interest one could amass a small fortune.
But then what? What are you going to spend hundreds of millions of CR on? You can’t take it to the next patch, nor can you purchase anything worth while.
If 10 people came in w/ 70 mil, bought level 5 EB, and stacked CR for about 45 days, they could actually buy OCD 7. 7 billion credits, 700 million payed back to the investors, and that’s it.
Without anything to buy with all those credits, and no way to carry them over to the next season, there is no real incentive to purchase something like this.
Here is a link to the spreadsheet w/ some precalculated info.
And as far as the new autominer system, 
Without the ability to target a specific ore type, they are virtually (pun intended) worthless. Who could possibly remember which one you bought first? Autominer cores as fuel seems outrageously expensive.
You will see in the spreadsheet above that using a level 10 gold AM, you can make 30k CR/day. That will also take 10 AM cores, which are not factored into the price. This will also raise the price of all the other ores if the economy uses a gold standard as its base.
But will the NPC traders prices change? I feel like these are good ideas, but very poorly executed. If AM cores are much more prevalent than in 5.0 this may not be a horrible system, so I guess we will see.