I think your solution of sending to different addresses would send a message... not sure it will solve anything though.

I always "assume" a seller will give a break on shipping if multiple items are purchased, I know I do.

There was a chip I needed on eBay... it was a cheap chip $2... but then I read the shipping charges... $1.50 Shipping & Handling, $.50 other Shipping & $1.00 Insurance. $3 to ship a $2 chip! Needless to say I didn't bid on the chip.

I will always look at shipping before I place a bid and I'm certain if someone didn't give a break on 5 items... I would remove them from my future purchases. I don't think it would be $1, afterall 5 chips weigh more than an ounce... but there should be a substantial, if not a token discount on multiple purchase at the same time... afterall, it only makes sense!