What should be the one time payment to 498a wife?

Yes if proved that she filed false case of 498A and DV, Than she is not entitle to ger maintenance becaouse If proved 496A/DV false Than naturaly 125 will be false its presumed by court, and this is not also sufficient ground for livinf separate,

and if living separate without any sufficient reason than wife is not entitle to get maintenance.

Under Section 125(4) of Cr.PC, if the wife is living separately without sufficient reason then the wife is not entitled to claim maintenance.

you query seems to be an outcome of a lot of frustration.

keep your cool and dont presume things, rely upon the advise given by the counsel who is handling your case.

there are not set principles of law in such cases.

Ad Kiron is right. If wife has good reason and evidence then story will be different and if wife has filed false case and can be proved then it will be taken that way. 

Court will decide whether her allegations are true or false..maintenance will be on basis of her self economic condition/earning.

And no court writes that she has made FALSE ALLEGATIONS UPON HUSBAND

And no court writes that she has made FALSE ALLEGATIONS UPON HUSBAND