“Good” data management practice costs money. However, “poor” data management practice may turn out to be far more expensive! When setting a budget for data management, you will have to consider budget headings for things like physical equipment, but also time. Some processes can take a long time to perform, not only system time. E.g. if you need to convert data to a specific format for archiving, you might need time to do the actual conversion, but you may also need time to make quality control of the output.
Writing data management plans, making data sharing agreements, evaluating repositories are also budget headings that might need to be funded – if possible – or at least taken into consideration when planning.