I will answer from both sides...since I buy and sell

As a seller, I charge $2.50 shipping and do combine. Actual shipping in most cases is $1.69. Once you add in the bubble mailer, labels, and possibly airtite, flip and insurance (depending on value)....in most cases it is near $2.50, in some cases it is more.

As a buyer, you can charge me whatever you want. I have a price I'm willing to pay "All-in". I take my all-in price, subtract out the shipping charges, and that's my bid. It doesn't matter if you have free shipping or charge $10, you get the same net bid from me.

But I will say that hearing other are attacted to free shipping auctions makes me think....

Also, one more thing for you ebay sellers to think about. If you are a "Top Rated Seller" according to ebay, they offer you a 20% discount on your final value fees. That discount is NOT taken on the shipping charges. May be something else to consider when setting your shipping charges.