What to charge for advertising?

I run a pretty small content site about a hobby, this is in a relatively high cost accessories niche. Product prices in this niche range from 200 - 1500 USD.

The site has the number one spot in google for a lot of relevant keywords, ranking higher than the actual shops selling these products.

I was contacted by someone who operates such a shop asking if he could advertise on my site. I have no idea what I can charge. I could provide details about how many visitors / pageloads I get but then he does not know that and perhaps doesn’t need to?

I realize this is probably very hard to answer but … what could I charge for a 125 x 125 ad block on all 15 pages of my site?

[FONT=“Verdana”][SIZE=“2”]For first ask how much he ready to pay. And it depends of cours from traffic voume on your site.

PPC Search Engines
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I would ask him first how much he would be willing to pay.

Firstly you can decide how much do you spend on advertising. Then you we will go further step.

Try and find out what some of your competitors charge roughly, that may give you a bit of guidance.