I believe that in class-conscious 19th-century England, tradesmen would extend credit to members of the nobility much longer than they would to an ordinary person (though Sir Walter was of course pretty low on the totem pole!) I remember reading that after one particular aristocrat died (wish I could remember his name), his tailor nearly went bankrupt because the man had never paid his bills, simply coming back for more. Maybe Sir Walter could "afford" to ignore his bills for a while longer as he retrenched?