Numerous gambling websites cant rank..

That would depend on the keywords, how many and how difficult and where the SEO Provider is located. If you're located in New York, life is more expensive than if you're located LaCrosse, Wisconsin. And LaCrosse, Wisconsin is more expensive than quite a few other places in the world.

But $150 is not enough.

Think in terms of what's needed: your SEO person will need some content that's optimized for each keyword you're going after.

And you want content that's not going to turn visitors away, so you don't want the $1.99 for 500 words. You want $50 or $150 (here prices vary by industry, weight loss would be cheaper than law, by the location of the writer, by how close to copywriting the article is going to be).

She or he will need to get backlinks. Not crappy ones.

Low quality are a lot cheaper, but you need tons.

Great links are more expensive. But you need fewer.

So, even for 5 keywords, you end up with hundreds or thousands of dollars.

The question is, how much is it worth to you.

If you made it to #1 for your top 5 keywords, how many visitors would you get? On average, it seems the top position gets you 30% of the traffic.

And of those visitors, how many end up buying?

And how much getting that is worth to you?

If someone's activity would get you $100 a month, how much of that $100 would you be willing to pay to get another $100 next month?

Then, there's the question of how much can you afford?