What if you were to imagine you were in the business of selling banners on your site and outsourced everything to do with the site?
Add the cost of site content contributors to cost of site SEO to keep it marketed well plus other costs, then divide the total costs of running the business by the number of available advertising places for banners. The banners support the site without profit.

You make your profit, not from the banners, but from whatever you are marketing on your site. Now it's a fully optumized and content maintained website costing you nothing.

If you are doing the SEO and providing content then pay that to yourself.

Thanks, familyman, but my site is very little for the time being and outsourcing things is out of question.

I was just wondering how to determine the value of a banner since somebody asked me directly for such an ad.

I think familyman was suggestion you IMAGINE you were outsourcing, figure what that might cost, and price accordingly, with an additional charge for your time and effort.

There is no equation to come up with a price, but it does make sense to price according to cost as much as possible, even if you are not now incurring those costs.

Another way is to look at what similar sites who publishs ad prices charge.

Or figure out how much you might earn from an Adsense ad in that spot and use that as a starting point - but with additional charges for your costs.

I'd figure how much I'd make having google adsense on the same spot. I'd double the amount, add current expenses and ask the price.

I see...thanks guys, I'll give it some thought.

There are some many formula's for deciding this. I think it is best to have the hotel place a bid, and it if works for you do it. (this is the easy way).

oh, why double price (my earlier post). Because, if you get google ads, those are framed, so search engines can't see them. While a normal banner is an outgoing link...