From the sounds of it, you'd be willing to pay a little extra for some bonus functionality.  Let me go back to the drawing board a little bit, and see what I can do about offering something that does it all on-chip, so that you can plug it into your router etc. at home and have it mine without a host.  USB will remain available for those who don't have an extra port on the router, and WiFi will be an *option* too, though it'll tack on a little money.
After some review, I'd like to make it clear that there will be a maximum of 4 expansion boards per main board. (Note that a specialized jumper tech is in the works, this number may increase)  This will be a limit imposed by firmware, and you can modify it if you like, but it will be unsupported.  The price of a main board won't be *that* much more, so getting 1 GH/s per mainboard-and-four-expansions isn't too bad for the price.  Not to mention the fact that it's modular.
As far as what my offering has that others don't, the modularity and Ethernet, as someone mentioned, are a plus.  Now, standalone functionality and WiFi capability will also be a bonus.  All of this in addition to the fact that my prices are competitive, if not cheaper than the going rate for FPGA miners.
Let me lay down a schematic that allows for standalone operation and I'll let everyone know what the price is looking like, so y'all have a better idea.  Spoiler: It will be more expensive given that it is standalone, but I can tell that that would be convenient for some of you, so I'll check it out.
Keep an eye on the post, and thanks for your comments!