I'm sorry, but that's completely wrong. Each interface has an IP address. Both switch and router ports can have multiple devices and IP addresses on each port. Some routers (AKA layer-3 switches) can have over 100 ports (and cost well into six figures).
For wiring, daisy-chaining switches is a bad idea. make a home run from the main switch to each floor's switch, but don't exceed cable 330' for each run (assuming CAT5 or 6).
each interface (or vlan) will have an ip address if running in layer 3. it wont if layer 2.
routers are not layer 3 switches, theyre routers.
layer 3 switches can perform routing functions.
some network topographies have homeruns from each floor's switch to a 'main' switch. Another way to do it is to daisychain each switch, but the last loops back to the first and OSPF is enabled.
bottom line is there should be a network engineer somewhere who designed this and specified the network equipment. Anything you do without knowing the network topography is purely speculative and may or may not be adequate.
as far as expensive switches, there are some now (high density 10GE switches) that run well over a million bucks fully loaded.
sidenote: I saw the wierdest thing one time, a fedex guy carrying a desktop pc size box. The fedex guy had a sidearm (semiautomatic pistol). I later found out that cisco makes a couple cards for their CRS routers (think the machine that routes ALL of Verizons traffic in and out of new york) that cost over a million dollars for ONE LINE CARD!! So I guess when you insure your fedex box for a million bucks they send an armed fedex guy....