I think all of that is not what the OP wants to do: use resources time, employee/labor hours, dollars, take up real estate), etc. and he can't have people into his store!
I'm surprised you can't bulk out some of these comics by the longbox? Everything sells, even if you have moldy or very poor quality over-printed Marvel/DC comics they will sell, even if it's $10 a box. Maybe this isn't feasible now, but I cannot see why in the past you'd be trashing comics. I bought a collection of 10k comics last summer, I bulked out about 10 of the 50 longs and I maybe recycled/tossed less than 15 comics. There was some real crud in there, graphic stuff from obscure no name publishers.....but everything does sell - at a price.