it really depends on what youre looking for. there's many services out there that will push your items and data out to ebay (auctiva included).
there's one service that will rent you webspace for setting up a website, and has software that will push your items out to various venues including overstock and ebay. BUT it's pricey. Zoovy.com Has a $400 setup fee, 2.5% of sales (with minimum of $74.95 per month), $10 per month merchant acct, 2.16% + 25cents per transaction for merchant acct fees, charges $80 an hour for customer support, and charges extra for each add-on-module, inventory mgmt, etc.
And even with zoovy, you'd have to create the site and create each individual listing on the site, before you can push it out to ebay, overstock, etc.
So, like I said, really just depends on what youre looking for. There's really not a simple/easy way to do it, though, unless your dropshipper will create your listing data for you (and/or push to ebay your listings), or unless you can afford to hire someone to do your listings for you.
the questions I have, though, is "if the dropshipper is going to create the datafile of your listings and push your listings out to ebay for you, why isnt the dropshipper selling it direct? could it be that ebay is already flooded with the items the dropshipper has and those people that do manage to sell them arent making any money?"
but anyway, like i said, just depends on what youre looking for, how much your willing to spend in assorted fees, etc.