Question: I need an adjective for the term "financially motivated." The word I'm looking for isn't exactly greedy or rapacious. Although it can have connotations like that, the word needs to directly mean something more similar to "he does his job well if there's money (or perhaps just incentive) on the line."

Thanks in anticipation.

Answer: 
The word you are probably seeking is ***mercenary***, which exists both as noun and adjective.

It tends to carry negative connotations and is applied more specifically than in any other context to soldiers of fortune, who fight, not for a national flag, but for financial reward. indeed that is how the term is applied as a noun. ***A mercenary*** is such a soldier.

Its etymology is from Latin via Norman French, though the earliest example the OED has, is from Chaucer:

> 
> ▸ c1387–95 Chaucer Canterbury Tales Prol. 514 He [sc. the parson]
>  was a shepherde and noght a mercenarye [v.r. mersenarye].
> 
> 
> 

The full range of OED entries for ***mercenary***, without the multiple examples under each sense, is as follows:

> 
> A.
>  1. A person who works merely for money or other material reward; a hireling. In later use (probably influenced also by sense A. 2): a
>  person whose actions are motivated primarily by personal gain, often
>  at the expense of ethics. c1387–95—1998
> 
> 
> 2.a. A person who receives payment for his or her services. Chiefly and now only: spec. a soldier paid to serve in a foreign army or other
>  military organization. 1523—1974
>  b. In extended use, with modifying word. 1861—1987
> 
> 
> B. adj. 1 a. Of a person, organization, etc.: working or acting
>  merely for money or other material reward; motivated by self-interest;
>  materialistic. 1532—1997 b. Of conduct, a course of action, etc.,
>  or its motivation: characterized by self-interest or the pursuit of
>  personal gain; prompted by the desire for money or other material
>  reward; undertaken only for personal gain. 1532—1990
> 
> 
> 2. a. Hired, serving for wages. Now: spec. designating a soldier paid to serve in a foreign army or other military organization; (of an
>  army) composed of such soldiers. 1569—1974 †b. Salaried,
>  stipendiary; profit-making. Obsolete. 1656—1782
> 
> 
> 	3. Of or belonging to a mercenary. a1616—1922
> 
> 
>
You might describe such a person or their worldview as **transactional**. 

In other words, this person makes an effort in a certain context because compensation is offered. Either broadly or in a certain situation, they might interpret their own and others' actions and expectations through the lens of a balance sheet—effort for its own sake is neither extended nor expected.

The term is not especially complimentary but is far less pejorative than the alternatives "greedy," "desperate," ""avaricious," "rapacious," "materialistic," or "mercenary" (!). It includes anyone who expects to receive a paycheck from their employer, for example. One could frame the behavior in a positive way by saying that the person is businesslike or practical in expecting a suitably compensated, mutually fulfilling professional relationship.