Assuming it’s a lifetime payment, and truly passive, I’d take the 10K a month for 120k a year risk free passive income for 30-40 years.
120k*.04 safe withdrawal rate is $3M.
As I think some others said, if one really wanted to, sell that 10K “annuity” for 2.5M to 3M and then do the strategy of buying assets etc, the others are saying, but now with 3M instead of 1M.
In doing comparison, I don’t think as many are factoring the risk and truly passive. Now risk for the payment, is it federal pension, insurance company, something else? Might want to factor that source of the payment in also. Is it pegged to inflation?
Perhaps I think of the 10K as similar to my military pension I’ll be receiving shortly where I’ll be getting 86k a year with cost of living increase. Sell that for 86K income for 1M? Heck no. It’s worth 2.15M and 120K is worth 3M.
Take the risk free 10K unless worried that will not last because of the source.
JT