Yes, both cost and performance! The best way IMHO to achieve high SNR in a tubed phono stage for low output MC cartridges is to use a step-up transformer. It provides impedance matching and noise-free gain. One of the few circumstances where positive attributes are not opposing.
The Trumpet is sold separately from the StepUp as a cost savings to those who do not need the high gain. As a matched pair, the gain and SNR is suitable for very high-end MC cartridges. The customer need only buy what they need and are not burdened with transformers if they aren't required. My goal as a manufacturer is to offer both value and innovation.
Sold together, the Trumpet and StepUp provide the lowest cost Stereophile class A recommended component solution in tubed phono stages. By a factor of two.
So yes, both value and performance. In my experience, the step-up is technically the optimal solution. Listening tests (my own research) confirms this.
Thank you for your interest!