We can not estimate a return on a fiat investment. You will need to determine which currencies are appropriate and we can help you understand the yields available and run the technology (nodes) to securely and reliably deliver your staking rewards.
There are significant differences between the underlying cryptocurrencies that are a very material factor in your overall investment analysis. The yields represent our best estimate of the amount of additional currency you will receive through staking. But cryptocurrency prices have been very volatile historically, and this can impact the return.