I wouldn't say that's too many, typically you should be tracking similar amounts with most campaigns to diversify in my opinion.
Pricing ultimately comes down to a few things :
- Your experience and ability
- The value of your time to get results "comfortably"
- The time scales anticipated by the client, i.e client expectations.
- The campaign metric targets, i.e only keyphrases improvements ? Or improved traffic and conversion targets ?
- Keyphrases competitiveness
- Sustainability of the campaign.
- Your primary strategies to accomplish the goals.
- Client budget
The fact you've highlighted it could be a problem in this thread would give the impression that it maybe it could be too much for you to take on or your strategy is more idealistic for smaller projects.
No one could realistically put a price on it for you without doing their own research into the company and phrases in question. We have clients on the books we target 100 total phrases ( 5 primary targets ) for only £500 per month because of the niche the targets set and it is a sole keyphrase campaign with no traffic or conversion targets ( more of a vanity campaign with mixture of money phrases ).
But we also have clients paying £2000 per month for 10 primary target phrases, conversion improvements and traffic improvement targets.
Every client is different and most of the time, need campaigns and pricing tailored to them.