Personal data is ubiquitous in the digital world, can be highly valuable in aggregate, and can lead to unintended intrusions for the data creator. However, individuals' expressions of concern about exposure of their personal information are generally not matched by their behavioural caution. One reason for this mismatch could be the varied and intangible value of personal data. We present three studies investigating the potential association between personal data value and privacy behaviour, assessing both individual and cross-cultural differences in personal data valuation, comparing collectivist and individualistic cultures. Study 1a, using a representative UK sample, found no relationship between personal data value and privacy behaviour. However, Study 1b found Indian (collectivist) participants' privacy behaviour was sensitive to personal data value, unlike US (individualist) participants. Study 2 showed that in a UK sample, privacy behaviour was sensitive to personal data value but only for individuals who think of themselves as more similar to others (i.e., self-construe as similar, rather than different). We suggest those who prioritise group memberships are more sensitive to unintentional disclosure harm and therefore behave in accordance with personal data valuations-which informs the privacy concern-behaviour relationship. Our findings can suggest approaches to encourage privacy behaviours.