Mostly good advice so far. You can estimate cost for transportation, daily rate and tips for DG which are more or less set. PG taken will simply add trophy fee, ship and taxidermy per each- so not hard to figure the add-ons to stay in budget. Take and carry a DG rifle that you can shoot well- it will also work fine for PG. The 375 HH and 416 Rem come to mind. A scope in the 1.5-6x range is plenty for either DG or PG.
Not that long ago, I would have included destinations like Zimbabwe, Zambia and Mozambique about equally in your possibilities for an affordable buff hunt in large to free range areas with varieties of PG. Right now I would look at a place like BVC in Zimbabwe. So large that for all intents and purposes, it's a free range environment.
I've done exactly what you are thinking of. Go for buff then see what PG shows up. No need in shooting a buff of any variety then get caught up in a feeding frenzy for PG. Chances are you will see a lot of the PG along the way... which sounds like budget eating ka-ching, ka-ching! If you enjoy this trip, you will be planning your trip back to Africa before leaving- guaranteed. No reason not to start a budget piggy bank while there if it works that way.
My advice is simple- learn to shoot that 375 straight and it will do very well on any PG. Use the right heavy tough bullet with proper bullet placement and it will be fine for buff. KISS! Use same bullet for all. Plan enough time for a relaxed hunt for an
old, hard-bossed bull with heavy, worn/broomed, possibly uneven horns- forget spread. Your PH will know exactly what that buff looks like and that description will probably make him smile
![Smile :) :)](https://cdn.jsdelivr.net/gh/twitter/twemoji@14.0.2/assets/72x72/1f642.png)
Along the way if a really good kudu or eland shows up... bonus! with known costs associated. Do not pass up a tracking attempt for a good eland! A good eland bull is, IMO, as impressive as a buff. Take time to relax while there and enjoy Africa. There are any number of places to do a lot of shooting. There's only one Africa. Read Hemingway, Ruark, Capstick, Bell, Selous, etc.
![Smile :) :)](https://cdn.jsdelivr.net/gh/twitter/twemoji@14.0.2/assets/72x72/1f642.png)
Enjoy the planning and anticipation.