What do you want to hunt and where do you want to hunt it? Want to keep any taxidermy? Going to use Air Miles or other points to fly or pay cash for tickets?
Some countries, Tanzania for example, are more expensive than others due to higher concession and trophy fees mandated by the government. South Africa can be remarkably inexpensive but you have to do your due dilligence - the running joke for years has been that anyone with 2 acres of land and a steenbok on it can call himself a PH in RSA. Some ranches can be huge - 100,000 acres but most are much smaller - say 10,000 - 20,000. Not tiny, but you're on fenced land hunting animals that, for the most part, are bought at auction and put out on the land. You can still have a rewarding hunt, but it will never come close to the experience of "real" africa where the fences keep the animals out not vice versa.
My first trip was to RSA in 2007. Total airfare was $3000, trophy fees and day rates about $9500, taxidermy about $3500 and shipping about $1500 (I'm not near my filing cabinet so I can't say for sure). My trip this summer to Zim is looking about $16,667 for daily rates, trophy fees, air charter and sundries plus dip, ship and taxidermy (I haven't received those bills yet). Add on about $500 in taxes for airline tickets booked on points and I'll be lucky to get out of it under $22K. That said, you don't pay for a safari in one chunk. I paid my deposit in January 2009, bought my tickets in October 2009, paid the balance of the day rates and fees in April 2010 and will likely receive my final invoice in the next month or so. Dip and ship a little later and taxidermy likely in 6 months. So spread the payments out over 24-30 months and suddenly the cost is easier to absorb. Save for a hunt like that over 5 years and nearly anyone can do it.