Penny wise, pound foolish

[Tdol]

You can find the definition of this English idiom here.

[GaryEM]

People who have this behavior - penny wise, pound foolish - are very shrewd, careful when poor. When they acquire much money, they become careless.

[blouen]

I would choose both of the selections.

[Tdol]

We tend to use it for those who throw money around carelessly, then get very concerned/mean over irreelevant sums. (BrE)

[George Mo]

This is an old expression that comes from England. A penny was a small copper coin with very little value, and a pound was a silver coin worth much more.

This idiom describes what happens when someone makes a poor financial decision because they're focused on inconsequential details. For example, buying an inexpensive car may seem like a good decision in the short-term (penny wise) but that overlooks the higher costs of maintenance (pound foolish).

The implication is that quality has greater value in the long run. This idiom is often used by salespeople who are trying to sell higher priced products.

[Uncle M]

There is another saying which seems similar but actually contradicts the example you give:

Look after the pennies and the pounds will take care of themselves.

This means that the habit of being very careful how you spend a little money will extend into being just as careful when you have an opportunity to spend much more.

Or, put another way, Penny wise, pound wise too.

Dave

[Reemy]

PENNY WISE AND POUND FOOLISH - "Overcareful about trivial things and undercareful about important ones. The literal image is of the person who fusses over small amounts of money to such an extent that he misses opportunities to save or make large amounts."

[theeexcellence]

Used for the person who is really cautious of overspending or extravagency when small amount is involved but carelessly casual when there are large sums of money to be made decision about -- (over-all) a bad manager of money.

[Huda-M]

penny wise and pound foolish

Stingy about small expenditures and extravagant with large ones, as in Dean clips all the coupons for supermarket bargains but insists on going to the best restaurantspenny wise and pound foolish. This phrase alludes to British currency, in which a pound was once worth 240 pennies, or pence, and is now worth 100 pence. The phrase is also occasionally used for being very careful about unimportant matters and careless about important ones. It was used in this way by Joseph Addison in The Spectator (1712): "A woman who will give up herself to a man in marriage where there is the least Room for such an apprehension ... may very properly be accused ... of being penny wise and pound foolish."