With bass strings there's a few ways to save, a good old trick is boiling the strings which can refresh them and make them sound new again. Boiling them can bring them back a few times and cleans them as well. Another option is to buy a quality set of flats such as thomastik infeld jazz flats. They generally have a sound in between upright bass and the piano bass sound, turn up the treble and you can get a reasonably bright sound and they last much longer and can be boiled. I would generally not cheap out on strings but for sure definitely save money by refreshing them