Health insurance is non-negotiable and shouldn't have an employee contribution. The rest of the benefits are more negotiable. 401k becomes important in your 30s when you start realizing that you're not going to be young forever. Conference budget is a nice-to-have but conferences shouldn't come out of your vacation-- that's a fuck-you if they do.

Regarding compensation: the total package should be enough that people don't worry about money. Ever. If you're doing your job, you may not make them rich but you pay enough that people aren't worried about daily living expenses.

The issue here-- why benefits are so important-- is that VC-istan startups are in such a state where the concerns of a 45-year-old with kids are seen as freaky and unusual. There's a very large talent pool that's being overlooked.