As I go periodically to South Sinai (St Catherine and El Tarfa) I have found many means of transportation with different costs.
Sharq el Delta bus (Cairo – Suez—St Catherine ) :
2 buses daily from El Torgoman (Ramses) and then from Almaza Station (masr el gedida)
From Almaza they leave at 11.45 am and 2 am, tickets are for 30 LE
It takes a very long time as it passes through Suez first. Usually they have the worst buses on this particular route, so you may not be satisfied by the cleanliness of the bus. also they constantly keep stopping as the bus engine keeps giving trouble.
Any bus to Sharm el Sheikh :
Many buses leave from Cairo from different companies like El Gouna and super jet. They leave periodically at morning or at night, tickets range from 50 LE to 80LE according to time and company .
Buses on this line are more brand new and with high level of maintenance. You can ask the driver to drop you at (Mafareq St Catherine or lagnet el mafare2 ) .
You should coordinate with a driver from St Catherine to take you from el Mafare2 .
Transportation from el mafare2 to St Catherine cost about 100 +_ 20 LE .
Here is a driver whose number you can call :
Shick Eid 0693470040.
This means of transportation is suitable if you are an individual and need to go there quickly and inexpensively with flexible time of leaving Cairo.
Car Renting :
As I go there periodically, sometimes I need to rent a car to be more flexible in time and transportation so I made a good deal with the car rental agency which I think is offering me a good price.
From the start of Cairo-Suez road to El Tarfa (25km before Catherines) by a car model 2007/2008 ( mainly Mitsubishi) for 400 LE (not including transportation inside Cairo which you can add 10 LE to 50 LE depending on the deal between you and the agency ) .
This means of transportation could be suitable for a group of 3 persons as it is faster, flexible as you can take rest whenever you want, you will have less waiting time at police check points and if u have heavy luggage, the car could take you from home to your final destination.
The owner of the agency I use, is called Adel and his number is 0103979759
Best of luck and hope you enjoy your coming vacations