I think the cost for a defibrilator is around 3000 Euro. If you really want to, buy one (team up with your sports club, your company or some friends) and gift it to your community. They'll find a busy place to mount it.
Most business have one here in Sweden and almost all public places like train stations, malls, hotels have one. Most taxis carry one to and can be alerted by 112 (the SOS number operators, 911 in the US) if they are close. Rural areas are the unsolved problem that these drones might help with.
An unused (hopefully) defibrillator needs to be periodically checked for battery levels and (I believe) some sort of diagnostics run to be certain that when/if needed it will be efficient.
Like with fire extinguishers or other periodical checks, most probably this must be done by someone qualified/specialized, which may represent a non trivial cost, I wouldn't be surprised if it was something in the 200-400 Euro/year or something like that, and probably every n (5-8?) years you would need to replace the device with a new one.
Besides, there is an issue (in non-restricted access placements) about theft and vandalism.
Vandalism and theft sure are problems, placing them in locations with either camera surveillance (bank foyers, gas stations) or 24/7 personell available might be solutions to these problems.
It has been introduced by Law only recently here (Italy) in a number of public places, and there are a lot of perplexities about the bureaucracy connected, the reliability of this or that model (or manufacturing firm) availability of spares, legal responsabilities of the provider, etc.
I believe (but I may be wrong as - as said - they are not yet common here) that the trend is towards some forms of "service" or lease/rent for the devices including their maintenance and all the bureaucratic paper and electronic work (by Law the device needs to be "registered" on a "online map").
Costs at the moment for this latter approach (rent + service) start from as low as 20 to something like 60 Euro/month for 48/60 months contracts, AFAIK, and they include an insurance against theft/vandalism, but it has to be seen how it will work out.
Some details of the norms around these are not clear (yet).