[throwaway76543]

It depends entirely on the cost to purchase. If it's a fraction of the opportunity cost you're probably crazy not to early exercise.

There are major benefits beyond tax savings. If you quit before a liquidity event you can easily keep the vested equity without worrying about paying taxes on unrealized gain.

[trjordan]

At anything other than really-low-valuation-seed-stage, the cost to purchase is going to be material. Since 409(a) is basically just 1/5th of the last valuation, at $5mil valuation, 1.0% equity will cost you $10k to exercise. If you can burn $10k without thinking about it on startup salary, this advice isn't for you.

If you wait, you get substantially more information. A company that makes it to a Series A has a much higher chance of succeeding, and you'll typically know that in your typical tenure of 1-3 years as a junior dev.

If you want to spend $10k cash on buying startup equity, at least call yourself an angel investor and go find a company that's willing to issue you a note that converts to preferred stock. It's too easy for a company to have a couple of missteps and wipe out most of the common stock value, even much later.

[throwaway76543]

It's strange to worry about a $10k investment while we're both acknowledging the investment by way of accepting a below market salary is an order of magnitude higher.

If you can't afford dropping $10k to buy your equity then you can't afford taking a $10k lower base salary -- let alone a $100k lower base.