If certain values are circumstantial, couldn't that just be combined into a higher-level formulation? Eg if a lower-class person values family, and a higher-class person values fulfillment, then you simply say "fulfillment is valuable when monetary and social needs are met" (aka Maslow's hierarchy of needs [1]), and that's something both people can agree on. No need to change anybody's circumstances.

[1]: https://en.wikipedia.org/wiki/Maslow's_hierarchy_of_needs