Cacao is actually grown in Uganda and Tanzania, so it ought to be possible to buy cacao beans direct from the farms.
Now if you are only able to work with blocks of chocolate mass, then it must surely be possible to arrange a deal with a chocolate maker, who wants good cacao beans and or a contact locally. to swap one for the other in some way. I know that this may be a lot more involved than you had intended. But otherwise, that is why you have to pay so much more.
I would seriously look at the possibility of working with beans direct from the farm.
Hello Alice, just seen your post inquiring about chocolates. Am from Uganda and i would gladly give you free cocoa beans samples from my farm. It will be cheaper for you to make the chocolates. You can reach me on email@example.com or Tel: +256-774-133427
C.E.O- PINK FOODS IND