How Much $$$ to Self Warranty for About 5 Years

[HEY32G]

Okay, a few days ago, I asked about warranty companies, but if I wanted to self warranty, from past experience, how much do you guys think I would need to put aside for future repairs?

For example (I'm making this up), if I bought a 2013 sdrive35i or 35is w/ 25,000 miles on it and plan to keep it 5 yrs, driving about 12,000 - 15,000 miles/year.

Thanks.