question:  How was Johnson convinced to buy the case astroid fever medication?
context: When Harvey staggered pontifically into the battered metalloy saloon—the only one on Planetoid 42—his tall, gangling partner was already stumbling out, mouthing something incoherent. In their hectic voyages from planet to planet, the pair of panacea purveyors had encountered the usual strange life-forms. Paying no attention to them, it was carrying a case of liquor in two hands, six siphons in two others, and a broom and dustpan in the remaining pair. The interplanetary con-men drank noisily, asked for more, until they had drunk eight glasses. Medical science is unanimous in proclaiming this magic medicine the sole panacea in the entire history of therapeutics." Our condenser broke down, and we've gone without water for five ghastly days." "And chief of police, no doubt," said Harvey jocosely. "On account of the quantity, I'm able to quote a bargain price. The planetoid man worked the pump while the mayor intently watched the crude level-gauge, crying "Stop!" when it registered the proper amount. Then Johnson rubbed his thumb on his index finger and wetted his lips expectantly. After giving them directions that would take them to the free-water pool, the ponderous factotum of Planetoid 42 shook hands and headed back to the saloon. "Johnson, as I saw instantly, is the victim of a difficult environment, and must charge accordingly." The figure, 750, with the bucko sign in front of it, was still doing acrobatics inside his skull and keeping a faint suspicion alive in him. "You don't need any more," said Harvey, dismayed. Johnson's eight-foot son, topped by a massive roof of sun-bleached hair and held up by a foundation that seemed immovable, had obviously been born and raised in low gravity. Harvey studied it worriedly, put his own hand somewhere on it, swallowed as it closed, then breathed again when his fingers were released in five units instead of a single compressed one.
output:  Joe's acting skills
options:  Proven statistics showing that it was the best antidote  Joe's acting skills  He felt feverish and thought he may have contracted the illness  A price too good that could not be turned down