I think the real first entry barrier is parts for protoyping. Its not as severe, since you can make packaging compromises on brassboard prototypes, but some parts are simply unavailable because manufacturers won't sell them to distributors and insist on NDAs and business plans to even get samples.

This service will help tremendously when it is time to jump from brassboard to final CCA. However, it is not feasible for most brassboard development because it requires redesigning and blue-wiring boards on the fly. The engineer working on the prototype needs parts on hand for this.