It is actually ridiculously difficult to find this information. However, according to some tender document I read some time back, it cost approximately Kes: 639, 319, 248 to construct the Kenyatta University Post Modern Library.
If you are interested in the cost of the other new buildings in Kenyatta University, heres some information.
Computer Laboratory Centre
Kes. 32,085,000
Science Laboratories
Kes: 66, 800, 000
Student Centre
Kes: 189,384,000
Lecture Halls
Kes: 128,087,000
Suswa Hostel
Kes: 67, 620,000
School of Economics
Kes: 211, 560,000.
School of Tourism and Hospitality
Kes: 59, 010,000
Amphitheater
Kes: 178,800,000
School of Engineering
Kes: 174,090,000
Nyayo Hostels two blocks
Kes: 211,260,000
Anatomy Laboratories Phase III
Kes: 45,000,000
Perimeter Wall
Kes: 45,000,000.