I went to search about Liberia.
First, it is not exactly cheap, by the offers I found on internet.
Interestingly, hunting consortium states, this is the best country for forest Duikers?!
I will qoute as follows
Liberia is inhabited by a very diverse palate of forest species, but only a fraction of these are currently huntable. Among the species available for hunting are highly prized species such as zebra duiker, water chevrotain, western bongo and dwarf buffalo. Liberia is the best location in Africa for hunting forest duikers.
Hunting conditions are tough and safaris to this country are designed for experienced Africa hands and serious collectors. Most hunting takes place at night, stalking along jungle trails, using spotlights in the thick rainforest. Camps are simple, rustic affairs, without many amenities. Temperatures are high, day and night, and the humidity is stifling.