I do not know the specifics of your HOA or governing docs.
As a general rule, if the walls are connected and there is now way you could reasonably be expected to tent or do repairs (eg a condo or townhome), the HOA is responsible for wood pest issues other than the interior of your unit.

In other words, if your window sills show swarmers, then probably you will get stuck paying for it.

However, if the whole building (again, assuming you share walls with your neighbor) has real issues, then it won’t be your responsibility.

As far as coming back, they will.

That is a virtual certainty.

This is san diego.

I think the termites even eat concrete here.

As far as the cost, that is rather low in an absolute sense but not so low in comparison to most attached dwellings. Its probably reasonable but I would want to see the report to say for certain.

The thing you should be most concerned about is who is responsible.

If you are buying into an HOA property, you should be clear very early on with regards to who is responsible for wood pest issues.

As an example, my friend bought a row-cottage (the kind that used to be built in groups of 6 or 9 in the 20’s). After finding termites, she approached the HOA to do some kind of treatment. She was disappointed to learn that the HOA does not offer any assistance on these since they are detached structures.

She did not review the CC&Rs when she bought and her agent at the time never went over it with her.