Hi guys, somehow I've missed this thread....
I think it sounds like a box of 'cheapies' is really the only way to approach this, the consignment deal is wrought with a number of reasons:
1) A store that appears profitable and well-run can change quickly and suddenly over time; the largest established LCS here in Ottawa is in financial distress (three locations, two of them being comic shops) has a large consignment collection for sale. There isn't a lot of big books there, but there's a ton of books priced in the double digits, several hundred at least....I doubt the owner will be getting all of those books back!
2) Knowing a guy that seems decent is not really any type of added security. As THT pointed out with his partner; I also got ripped off a year ago shipping comics to a dealer (low amount) that I had known for over 20 years - he ran the local LCS that I visited as a kid! It was a small amount, but the principle of it really, really pissed me off.
...why I think a longbox of cheapies is the only way to go. I don't know if it's the stigma of LCS being expensive for back issues, but I don't know many people that shop or look to shop there for those type of comics. Also, I find that being in a retail setting, LCS do better moving books at prices ($2/$3/$5,etc.) than I would have at shows at those same prices. So if you can get 2-3 $1 longs, 2-3 $2 books, 2-3 $3 books and one $5 box you should be able to move $3-400 in inventory with just the minor additional operating costs of stocking the boxes maybe twice a month? Not really additional work needed and you probably already have buyers lined-up like you suggested.....factor in maybe 5-10% of this cannabalizing some of your existing sales and theft/damage and you're still doing well!