Even cheap (Shimano UN-XX) bottom brackets usually last several years (IME), enough that the two I had replaced within 6 weeks on two different bikes were both frozen to the frame. It's a hassle to get them out, and if it takes a month of soaking (as the last one did) to remove it, you're without a commuting bike for that long. (Which is a great argument for N+1, but I digress.) After discussing with a few mechanics, I re-installed both new BBs with Teflon plumbers tape. You could also do annual maintenance on the BB, and grease them annually. (That's more hassle than I put up with.)

Or you could get one of the SKF bottom brackets. They're expensive, but sealed, and likely to last a very long time. I'd still install with Teflon tape.