Please explain the meaning of the related passages from "The Gift of the Magi" by O. Henry"...until one's cheek burned with silent imputation of...

Since O. Henry's stories are set at the turn of the
twentieth century, much of the situations and settings are, of course, relative to this
time period during which there were small specialized shops in which individual
owners ran their businesses. With these privately-owned shops set in neighborhoods, the
clientele of such businesses became familiar to the owner and his help.  Therefore,
since Della Dillingham had almost daily contact with the grocer and the vegetable man,
she felt some embarrassment when she haggled with them over the price of their products,
for it was insulting to these shopkeepers who were probably generous with an extra chop
or bunch of broccoli, for instance.  She feared they would think she was just being
stingy when she "bulldozed" them.  An "imputation of parsimony" means an accusation of
stinginess.

Then in O. Henry's description of the flat
(apartment) in which Della and Jim live, the narrator remarks that the rent is eight
dollars per week.  This is a fairly low rent, so although it is not rundown beyond
description ("beggar description"), it "had that word on the lookout for the mendicancy
squad"; that is, the apartment was very close to appearing to be a place where  homeless
beggars would dwell.  The mendicancy squad was a police squad that picked up beggars and
the homeless in the time period of the story.  The Dillinghams are poor because in 1906
there was an economic crisis developing, one which was made worse by the major
earthquake in San Franscisco.