It is completely reasonable.

Bitcoin Only - It is easier to accept BTC, and they need to move money fast to pay suppliers

No Refunds - This protects Avalon against people freerolling them as a hedge against BFL.  If Avalon allowed refunds, and BFL shipped both on-time and within-spec, then nearly every rational buyer would ask for a refund, due to the 65nm vs 110nm efficiency gap.

No Proof - They are just being honest here.  No amount of pictures / video will satisfy the doubters (but seriously Avalon, how about a video of a unit hashing...) and they are trying hard to expedite the delivery of the first unit to Jeff.

I predict this batch will sell out, regardless of wether it is a good investment or not.  At a minimum, many miners are irrationally optimistic and will eagerly preorder anything that hashes.