It would only be possible if they were counting any debt that Henry would have accrued during his French campaigns during the time period. Even withstanding these debts the King's lands were far more wealthy than the Duke's.

The last year of Henry VII's reign gives an estimated income of roughly 40,000 pounds. This was a sum that had risen heavily in the decade previous where income levels had been roughly 25,000 pounds per annum. In comparison, when royal servants and the (late) Duke's auditor evaluated the land in 1521 after Edward Stafford (Third Duke of Buckingham) had been executed they valued it at just over 5,000 pounds per annum after operating costs and this is a high end estimate given that upon his inheritance the Duke found his lands far short of those numbers.

This also has to be viewed with the absolutely staggering inheritance that Henry VIII received upon being crowned, which is estimated to be 1.5m pounds. This is a fortune that Henry VII had worked from the first days of his reign to build and that he would cause considerable political strife in building with his relatively low born ministers achieving positions of high power and binding the nobles of the land with financial bonds.

Winter King:The Dawn of Tudor England by Thomas Penn

The Plantagenets by Dan Jones

Edward Stafford, Third Duke of Buckingham, 1478-1521 by Barbara Jean Harris