Still if they can build one it seems to be they should be able to make as many as they want as the real costs for ASIC are development, not manufacturing. Manufacturing is just logistics and china has that crap down, there's hundreds of companies there they could farm it out to if they wanted.
The only other option is they faked the ASIC and its a bulky front end to a Fpga farm somewhere on the net.
Many things can go wrong in a way that yes it is possible to produce a few ASICs that work, but due to glitches, localized power issues, localized heat issues, etc, the vast majority of chips fail and yields are so poor you have to just start over.
Hardware design debugging is infinitely more complex / frustrating than software debugging. With software you have a debugger and can step through the state, with hardware you have timing analysis tools, power tools, etc, etc, which all say the chip should work, but for some reason only 1% seem to function and the rest perform abnormally.
If Avalon's shipments are slow, then they have a yield problem probably related to the design, and that is an issue. If the yield is bad enough then even $2,000 for a unit may not be profitable.
Having done lots of sub-nm ASIC designs, I can say a bitcoin ASIC is tricky because it is a highly compute
dense design which stresses the on-chip power rails, causing propagation issues on the clock network and all sorts of other issues if you are not very careful and conservative in the design's timings...
I don't mean to be spokesman, just pointing out what they said for reference. 
