Much good info above. Most definitely, the #1 thing to look for in my opinion would be an outfitter that has had TRADITIONAL archers there, and had repeated success. I know multiple people who went on archery hunts (both South Africa and Namibia) and ended up with either limited success or resorting to rifle hunting because of either being way to far from the water for shot opportunites (one place a friend went to the CLOSEST shot was 35 yards), to many water holes that the animals didn't have to come to certain spots, or the animals were hunted so hard with guns the only time they would water was at night.
For my first trip, I corresponded with over a dozen different outfits trying to decide which route to go. All welcomed me with open arms when I mentioned archery hunting, but only two out of all of them seemed to welcome my trad gear. I ended up going with Dare to Bow after multiple referrals and the fact that the owner Lammie was a traditional archer himself, and all of his setups were placed with the intent of hunting with traditional gear. Not only was I drawn to this place by him being a traditional archer, but also because it is a smaller outfit that only runs one or two small groups a month keeping more personalized and detail oriented, as well as his prices were about as good as I could possibly find. I have never looked back or regretted my decision on choosing his outfit, so much so that I just returned from my 4th trip and already talking about my next one!
Costs will vary from one outfit to the next depending on animals you want to hunt and length of stay. Package hunts are typically the best bang for you buck so to speak as you can typically get all of your stay covered (lodging, meals, laundry service, trackers, guides, skinners, ect.) as well as a group of animals to hunt. Any additional animals can typically be added in on top of that per the trophy fee list. Flight prices vary depending on time of year and which route you decide to fly ($1200 to $2000 is pretty much par). Getting your animals back is also something that can vary a bit depending on what you want done to them. For my last trip, I had 5 animals shipped back (skulls and capes), and with all costs tallied up (skins salt tanned, skulls cleaned and bleached, crating, and shipping costs) I had right at $1100 in them.
If you have any questions at all, feel free to ask!