Dear GYE,
My husband struggles with internet addiction.
Dear Balancing,
The balance between controlling and stepping back is a tough one for the spouse of an addict. You may want to discuss this more in depth with our spouse experts (see this page).
You could perhaps simply ask your husband straight out if he feels eBay is safe for him? As much as you don't want to try to control, would you have a lingerie shop in your house?
If your husband is using the TaPHSiC method (which involves a shvuah and doesn't rely only on filters) then he will probably be able to keep eBay. (Click here for a 40 minute shiur on the TaPHSiC method, or click here to read about it).
We push this method strongly on GYE because filters are almost NEVER a real solution. There will almost always be loopholes or unfiltered access somewhere, at some point.
But if your husband IS relying on the filter to protect him, then I would suggest that you ask TAG to block it, as hard as it may be for you. That is a sacrifice you may have to make for your husband's sobriety.
People have lived for thousands of years without the conveniences of eBay and Amazon, so if these sites are stumbling blocks - which they definitely can be, we should get rid of them.
Another option may be to use a smart filter like Nativ USA or www.vcf.co.il which can either block images completely on specific sites, or detect skin color and block parts of images (although I can't vouch for the reliability of this feature).
Hatzlacha!