Community-based tourism (CBT) is deemed a powerful means for enhancing community well-being and ethnic cultural preservation (CP). However, its sustainability has been challenged by resource scarcity, environmental pollution and funding instability in Vietnam. This study investigates young tourists’ perceptions of and financial contributions to community-based tourism associated with cultural preservation (CBT-CP) at Lac Village, a key White Thai ethnic site in Phu Tho province. Specifically, the contingent valuation method (CVM) coupled with an interval regression model was used to analyze the data obtained from 275 respondents during December 2024 to estimate the willingness to pay (WTP) for CBT-CP and identify influencing factors. We found that nearly 50% of the respondents are willing to contribute financially, with an average of roughly USD 4.45 per visit. This leads to total contributions of USD 2413 for all respondents and USD 1541 for respondents with a high certainty level of commitment. Additionally, we found that key barriers to WTP for CBT-CP are fiscal transparency concerns, personal financial limitations, and individual determinants. These findings offer many policy implications for mobilizing young tourists’ untapped funding, strengthening local management capacity, and advocating for enhanced transparency to improve CBT-CP in the study area and beyond.