What are you considering high?
Looking at ads here on AH and elsewhere, I've seen day fees on the high end at over $1000, usually in one of the more exotic hunting countries and for dangerous game. When the hunting camp is more off beaten track, the day fees will be higher as its more expensive the outfitter to bring in food, power, clean water, etc.
I think on average, in countries like RSA and Namibia, day fees will range from $200-$450 for PG, more for DG. Day fees will be more in places like Mozambique , Botswana, Zimbabwe, etc. Even higher in CAR, Ethiopia, etc.
On the other end of the spectrum, I've seen outfitters that don't charge any day fees (this just means that cost is rolled into the trophy fees).
When it comes to planning and budgeting for your safari, I recommend figuring out a ballpark figure you want to spend- $5000, $10000, $30000, etc. Then decide what animals you're after- is there high cost animal in there (buff, sable, a cat), with an understanding that you can probably hunt at least 1 animal per day unless you are very selective on horn length.
After you've for the basics figured out, I recommend checking out the deals on AH. Even old ones. See who's offering what you're looking for and then contact them. The outfitters on this site will jump through hoops and bend over backwards to meet expectations, budget, etc.
Best of luck.