How much income will renting cards bring

I looked at prices for golden epic cards today. The Lava Launcher card is $9-$10 right now.

You can rent this card for 17 DEC per day. This is 6200 DEC per year or 60% per annum. But if the price of DEC increases several times, the yield will be hundreds of percent per annum.

The same rental prices for other golden epic cards.

On May 11, DEC costs $0.001, let's see what the income will be in a week and a month from renting these cards.