With cost overruns in much of recent rail infrastructure, I wondered if the quoted £20m would be enough. Network Rail opts for a carbon copy approach to the new station design. You would think this should bring costs down, but when I looked at the costs of recent station openings, there is a massive amount of variance. Below is a list of station openings recently (Barring Brent Cross East, as it has been over-engineered, so it is an unfair comparator).
It surprised me how much difference there is; what I am taking from the above is that where there is a higher cost, this may be down to local considerations, such as the station being on a viaduct. £20m based on today's prices may be enough, but the risk is inflation and how long it takes to get spades in the ground.
Some comments have been on whether Houchen may offer this money as jobs for friends. Anything on railway land must be designed and commissioned by Network Rail, including a selection of contractors. There will be more limited ability to play with pork barrel politics unless he uses a friend as a middleman, who then creams off a hefty commission.