I think you are mistaken here. Phase one, as shown by table 6 on page 19 of the rules, is introduced by the start of the game with no yellow tiles available. Phase 2 is introduced by stock round #1 when the yellow tiles become available.
The rules state:
4.1.2 Major companies are allowed to lay one or two tiles per turn. The ability to lay two track tiles and the cost of doing so depends on the option chosen for that company during it's first Operating round (see 4.1.3.below). Minor companies may only lay 1 tile per turn.
4.1.3 In the first operating round of a major company the director of the company must choose one of the following alternatives: 1. The right to lay two tiles in an operating round does not come into effect until phase 3 (see errata). 2. The right to lay two tiles in an operating round is gained immediately but must be paid for whenever it is used. If this option is taken, whenever the company lays two tiles in an operating round it pays the bank the following rates.
(etc.etc.)
In phase 2, there is a cost involved if a director takes option 2 of the 4.1.3 rule above. Otherwise he may not build two yellow tiles until phase 3, but there will be no cost invloved if he waits until then.
Yes - you are right. Now that I check I see the new version calls the yellow tiles phase 2 . I was thinking of the retuned version of the original game - which kept the traditional 18xx phases ( phase 1 being yellow ) and didn't allocate a phase to the contract bid portion of the game. My feeling is this change is an unnecessary deviation from standard 18xx which not only contributed to my error but also lead to their own errata in Rule 4.5.15! Why not call the contract bidding phase 0 ?