【Excessive】 , 【immoderate】 ,  【inordinate】 ,  【extravagant】 ,  【exorbitant】 ,  【extreme】  are comparable when meaning characterized by going beyond or above its proper, just, or right limit.

【Excessive】 implies an amount, quantity, or extent too great to be just, reasonable, or endurable.

【Immoderate】  is often used interchangeably with  【excessive】 , but, distinctively, it may imply lack of restraint especially in the feelings or their expression.

【Inordinate】 implies an exceeding of the bounds or limits prescribed by authority or dictated by good judgment.

【Extravagant】  often adds to  【excessive】  or  【immoderate】 the implications of a wild, lawless, prodigal, or foolish wandering from proper restraints and accustomed bounds. The term often specifically implies prodigality in expenditure.

【Exorbitant】 implies excessiveness marked by a departure from what is the customary or established amount or degree; it typically connotes extortion or 【excessive】 demands on the part of the agent or the infliction of hardships on the person affected.

【Extreme】 implies an excessiveness or extravagance that seems to reach the end of what is possible; it is often hyperbolic in actual use.