How much should to pay for SEO per month?

it depends on how high you want to rank and how hard it is going to be to beat your competitors.

 

Depends upon your website niche and keyword on which you want to rank your website on various search engines and competition on those keywords..
It also depend on the location (varies from country to country ) as well .

 

Browse through this link: http://tutor.rs
You can find tools that could help you do SEO yourself with a little knowledge.
Also you can find services that are offered.
Thanks!

 

Its like anything else. "Pay bananas, get monkeys"

So what do you do when you want to buy a new car? You research specs that are ideal for you, fuel consumption, size, seats, doors, colors and then you shop around. See who offers what for what price.

Same thing with SEO. If you want results, go to a reputable company, give them your details and await a quote. Rinse & repeat until you get an average figure and pick which one suits most.

Your request in this thread however, has no details about your website, niche, what you are looking for so I don't think you're going to get much of an accurate figure.

 

In my opinion everything depends from niche you work with. Scottlpool2003 said you didn't give any details and he has right, it's necessary in this case to figure something out.