Maybe a small local japanese shop in NYC carries a Topre keyboard for you to test out. Otherwise consider a KB meet up to try out other people's keyboards.
The policy to allow customer returns on opened items because of personal dissatisfaction is rare for small business vendors. Technically the item can no longer be sold as new, and if the vendor abides by this premise, then they stand to lose money with reselling many good functional returns as used items. This can be an big impact on overall sales for a vendor with a relatively small number of SKUs versus a big box store with hundreds of thousands of SKUs.
Costco/Target/Walmart, for instance, can stomach your returns on used items. But a small mom n pop store would probably be like, "WTF, no!"