Something like, "you're arguing about the drapes but you don't even want to buy this house." Haggling over a deal that you don't want to close (or isn't yours to close). That sort of thing.
Penny wise, pounds 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 restaurants -- penny 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." [c. 1600] (American Heritage)
This isn't exactly what you wanted but it might work depending on the context.