While there is substantial research on what people want in their romantic and sexual partners, much of this work focuses on WEIRD, youthful samples, fails to consider the role of undesirable characteristics (i.e., things people do not want in partners) at all, or in conjunction with desirable characteristics (i.e., things people do want in partners), and may be overly reliant on psychometric approaches to pivotal variables in mating psychology like mate value and sociosexuality. In a nationally representative (online) sample of 2280 people from Czechia (aged between 18 and 50 years old), we examined linear and quadratic age, education, and self-perceived mate value (desirability) effects on the desired levels in mate choice of eight undesirable and seven desirable characteristics in men and women in relation to ostensible metrics of mate value. Self-perceived mate value alone explained little variance (men 1%, women 2%), while all mate value and mating strategy indicators together explained little variance of mate preferences and aversions (men 3%, women 5%). Desirable characteristics were better explained by mate value than undesirable ones. Our results are in line with evolutionary predictions suggesting that women are more demanding. Also, more qualities to offer correlate with more expectations in a partner.