How much biological material can be transferred in one transportation?

The answer is very simple, you can transport as much biological material as you need. The price for such transportations is directly influenced by container type and its capacity. If we are talking about the container type and its capacity there are two most common types of containers:

• small 2,5 litre container. This tank holds 3 cryo canes, 15 cm long, and depending on the type of carrier on each cane there can be attached 3 vials or one plastic goblet with 7 straws.
• big 4 litre container. This tank holds 13 canes, 30 cm long. Depending on the type of the carrier, per each cane, there can be attached 5 vials or two plastic goblets with 7 straws.

As long as the total number of vials or straws fits any of those tanks, you probably will be offered some fixed standard price for the transportation. Increasing the number of carriers means just a combination of few tanks for transportation and in this case, the price depends on how many tanks are needed for such transportation.