It's a lot more than £5 million, as the cost of the initial (very predictable) **** up needs to be added and that would fix a lot of the potholes that not just damage cars, they put cyclists at risk.
Apart from most of them being not fit for purpose and installed where they 'fit' rather than where they're needed, cycle lanes send out the wrong message (that bikes shouldn't be on roads), and statistics show the main collision areas are at the point the cycle lane rejoins the carriageway.
Shared bus lanes are an even bigger farce, as if they ever became popular with cyclists, the bus timetable would fall apart and in the interim, they sit cyclists in more polluted areas, and in harms way with buses and also with pedestrians and vehicles as the lane ends and bus stops.
I think that getting the same people that made the (very predictable) mess in the first place isn't reassuring, and rather than painting random lines on roads, spending the money on educating people on better shared use of the highway would be less fractious and create a safer environment and save a lot more money over all which could be spent on improving the road surfaces. It would also get cyclists off the footways, as that's a risk to all.