Sorry to be blunt, but this approach used to work 8-10 years ago when there was just one WiFi laptop every 4-6 apartments. Nowadays this is close to impossible to achieve this way.
You should be looking at placing one AP per apartment... or at the very least, one AP per two apartments (place the AP as close as possible to the adjoining wall between two apartments). Ruckus does a lot of MDU/apartment/hotel work (in fact, Ruckus is the leader in this space) and nowadays it is all about placing an AP (usually the H510 wall switch or the R310 ceiling mount AP) inside the room/apartment.
If cabling is an issue, look into the C110 AP which is very similar to the H510 but with a built-in DOCSIS modem so you can reuse the TV coax network as your uplink. Of course this will need expertise in fine-tuning, balancing and troubleshooting a coax network so you may wish to partner with someone with some experience.
Your cost might be the same as using outdoor APs since the H510 costs 1/4 as much as an outdoor AP.