Reasonable CPM for banner advertising

[rambo3]

I have a site which is getting around 1.5k hits a day. I have some adsence and affiliate ads already on the site but the main banner earns practically nothing with adsence so I was thinking of approaching advertisers and sell it on a CPM basis. I was thinking of charging around the $2 per 1K for the banner does this seem like a reasonable figure? Should I even bother trying to get a advertiser to pay CPM for a banner? I do currently have affiliate banners lower down the page, which get clicks but have poor conversions.