A standalone drive to use with Time Machine is almost certainly cheaper than an Apple Time Capsule.
Having said that, I have a Time Capsule (henceforth: TC) and I'm very happy with it. I need two WiFi access points to cover Hyph Castle and the TC performs admirably in this regard, as access point #2.
The primary access point is my ISP router. Or more correctly, the far better router that replaced the useless junk my ISP provided. I have a (very long) Ethernet cable connecting the two together. The TC is configured to use the ISP router as a gateway. Both are configured with the same WiFi SSID and password and clients switch seamlessly between them. Works very well, and my MacBook does backups from anywhere in the house without any intervention on my part.