I agree, a tour solves many of the audition problems. But tours can become a real hassle.
Folks sign up to audition, then cancel or want to reschedule. Ideally the shipping would be set up to minimize mileage/cost/time, but the cancelations and delays happen. Shipping damage or product abuse also happens. Some folks just fall off the face of the earth, have a change of plans, personal emergencies, or just a change of heart. The product take longer to get from place to place than you'd think (for instance some can audition during the week or only on weekends, or their free time only comes up certain weeks/months). Don't forget about shipping cost (even using a single container, which would have to be reinforced to hold up to multiple packing/unpacking/trips). And the tour coordinator has no real control until/if the product comes back.