Generally, money equates results. Depending on the arrangement and production style, you can more or less get away with a combination of sample libraries. One of the composers I work with will do this when a show's budget does not allow for a live session. The combination of experience in proper arrangement and orchestration for big band, coupled with cherry-picked patches from a variety of libraries, coupled with a proper mix including EQ and reverb will get you 95% of the way there. The downside to this is that you have to cater the arrangement to the capabilities of the samples, which typically only give you access to the most common styles and articulations.