Clue: Medicinal plant, originally at £50 topping list, we're told (7)
Answer: ALLHEAL
Explanation: Definition: Medicinal plant
definition: a name applied to a number of herbs used as medicine
 
A-t, plus L (libra, pound, "£") plus L="50" in Roman numerals, plus HEAL which sounds/"we're told" like 'heel'=to lean to one side="list"