X就X吧 / X了就X了: so be it, so what
【六57】【六66】口语格式 / fixed patterns
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
X就X吧 accepts a less than ideal situation: you repeat the word and close with 吧 (等就等吧 "fine, we'll wait"; 贵就贵吧 "so it's expensive"). You give in gracefully, because there is no other way or because something else matters more.
X了就X了 plays down what has already happened (坏了就坏了 "if it's broken, it's broken"). It is almost always followed by a reason or a rhetorical question that shrinks the problem: 有什么大不了的？ 没有什么好……的.
The word is repeated in full, 了 included. Register: spoken, a shrug of the shoulders. Do not confuse it with 算了 ("forget it", below), which drops a plan, whereas X就X吧 accepts it and carries on.
Examples
等就等吧，没有别的办法了。
Děng jiù děng ba, méiyǒu bié de bànfǎ le.Fine, we'll wait: there's no other way.
贵就贵吧，只要质量好就行。
Guì jiù guì ba, zhǐyào zhìliàng hǎo jiù xíng.So it's expensive: as long as the quality is good, that's fine.
累就累吧，反正明天不用上班。
Lèi jiù lèi ba, fǎnzhèng míngtiān bú yòng shàngbān.So we'll be tired; we don't have to work tomorrow anyway.
手机坏了就坏了，正好换一部新的。
Shǒujī huài le jiù huài le, zhènghǎo huàn yí bù xīn de.So the phone broke: all the better, I can get a new one.
输了就输了，没有什么好难过的，下次再来。
Shū le jiù shū le, méiyǒu shénme hǎo nánguò de, xià cì zài lái.We lost, so what? There's nothing to be sad about; we'll try again next time.
错过了就错过了，没有什么好后悔的。
Cuòguò le jiù cuòguò le, méiyǒu shénme hǎo hòuhuǐ de.It's missed, it's missed: nothing to regret.
Common mistakes
✗ 等就吧 → ✓ 等就等吧 (repeat the whole word).
✗ 坏了就坏，有什么大不了的？ → ✓ 坏了就坏了，有什么大不了的？ (了 is repeated too).
✗ 很贵就很贵吧 → ✓ 贵就贵吧 (only the bare word is repeated, without 很).