It comes down to the marginal utility of your money vs. the upgrade.<p>For example, I fly Singapore to Tokyo about once or twice a year, sometimes more often, always on Scoot, a budget airline run by Singapore Airlines. Upgrading from economy to ScootBiz costs as little as $80 with their &quot;bid for biz&quot; program. I always &quot;bid for biz&quot; and it&#x27;s absolutely worth it: early boarding, free food, much more space (for yourself and your carry on), etc. So the marginal utility of the upgrade for me is worth more than $80.<p>At some level of net worth, flying First on a legacy airline to Tokyo, maybe Japan Airlines which I had to take in economy once for $1,500 vs the $200 or so Scoot can go down to, would have more utility to me than the $10,000 extra I&#x27;d have to fork out. I don&#x27;t know what that net worth would be (probably north of 50 million), but I know that past perhaps a few million dollars in liquid assets, I would always fly business even at 3x the cost, and I know plenty of people in that situation doing exactly that. And there&#x27;s people for whom flying SQ Suites [1] for $30,000 one way is a &quot;discount&quot; from flying the same route privately.<p>[1] reposting because such a fun read: <a href="http:&#x2F;&#x2F;dereklow.co&#x2F;what-its-like-to-fly-the-23000-singapore-airlines-suites-class&#x2F;" rel="nofollow">http:&#x2F;&#x2F;dereklow.co&#x2F;what-its-like-to-fly-the-23000-singapore-...</a>