There will be no collision, no traffic jam. It costs relatively low. 10BaseT network will be abundant soon, perhaps in 3 years. Since connection between UCSB and Internet has a 10Mbps bottleneck, 100BaseT at the LAN cannot solve the problem for remote video conference anyway. 10BaseT switches can be consider as the first step of the network upgrade.
Network traffic is reduced.
Newer systems will enjoy the top speed at the 100BaseT segment. It is ready for the future. The older system can enjoy the improved lighter traffic at the 10BaseT segment. Collisions exist in each segment. That can cause traffic jam.