At best / at most (充其量)

Structure 充其量 + (只是 / 不过是) + low-end estimate

充其量 (chōngqíliàng) marks the MAXIMUM of an assessment in order to play something down: "at best, at most". 这充其量是个借口 = "this is at best an excuse". Unlike a plain 最多 ("at most", a neutral quantity), 充其量 always carries a deflating, dismissive edge: it says something amounts to no more than it appears, and it often pairs with 只是 / 不过是 ("is no more than…"). It is a written, cultivated expression.

Examples

这zhè充chōng其qí量liàng只zhǐ是shì个gè借jiè口kǒu，算suàn不bù上shàng理lǐ由yóu。
This is at best an excuse, hardly a reason.
他tā充chōng其qí量liàng算suàn个gè业yè余yú爱ài好hào者zhě，谈tán不bù上shàng专zhuān家jiā。
He's an amateur at best, by no means an expert.
这zhè笔bǐ钱qián充chōng其qí量liàng够gòu付fù一yī个gè月yuè的de房fáng租zū。
This money is at most enough to cover one month's rent.

Levels are indicative: they follow the standard Chinese Grammar Wiki (AllSet Learning) progression, not an official HSK 3.0 mapping. We never assign levels by eye.

This point and the other 370, with audio on every example, inside Wanyu.