Hello Lisa,
That sounds like an awful lot of money to spend, and I might be tempted to take a pragmatic approach, which is to provide a home-made solution. I assume you have a high-speed broadband connection which may be enough to power a number of flats, bearing in mind that our kind of tenants tend not to be the gamers who require huge bandwidth at all hours of the day.
I would therefore be inclined to do what hotels do, which is to install a mesh network originating from the router you have, and simply building out to all of the points where you wish to have a wireless network. There are many mesh networks on the market. Here is the newer version of one we have installed in our house and garden and it has been working faultlessly for many years: https://www.tp-link.com/uk/home-networking/deco/deco-m4/
Now what I don’t know is if there are any legal implications et cetera however, I assume that if you provide the service free of charge, you would not be deemed to be a reseller of bandwidth. It’s pretty well what hotels and restaurants do.
Happy to talk – 07401489832 (phone or whatsapp)
Christian
Lambourn Almshouses
PS. We do not have this installed at our almshouses, because our residents have not expressed any desire to go online!