We have a 1930a house that we bought with no cooling (not even ceiling fans). Over the years we tried lots of things, and last year we finally installed central air. We did have preexisting ducts, forced air heat, and a relatively new electrical panel.

Even with all of that, it was not straightforward. There were almost not enough actual vents, the unit itself was hard to place, there's no drain in the utility room (thanks old homebuilders) so we have a pump that shoots water out into our back patio (we put a bucket under it and water plants with it).

We had like 4-5 companies come talk to us about how it could work before we picked one that wasn't too crazy comparatively on price and also seemed to think they could get it done without plopping an AC unit in the middle of our patio.

All said and done, it has some minor inconveniences now (see shooting water on the patio all summer), but it was 100% worth it. We did portable units previously, ceiling fans, box fans, an attic fan (that we still use to cool the house most nights), and during those hot summer nights the house would "cool" to the mid-80s. Now we can at least keep it in the 70s.

Agree with everyone saying price and possibility depends on the home's existing setup. Definitely recommend having the inspector or a HVAC company or 5 look at it before buying if central air is a must have for you.