I'm not sure if it's been said anywhere else (I've had a look but can't find the answer), what's the odds of the HEMS bases having the capability to have more than 1 helicopter? There are a few HEMS charities in the UK now who occasionally run two from an airbase.
I'm also using HEMS to cover for UK CG SAR helicopters at the moment and there are two at each of the ten bases. Paramedics on board but not CC trained. MY CG bases currently can only run one helicopter which is a bit of a nuisance.
HEMS bases can have up to 3 helicopters looking at the expansions (someone may correct me to say it's between 4 and 6). Each expansion costs 1m credits with the further 300k for each helicopter - exactly the same as having a new base built.