While I agree that it SHOULD be part of the equipment they provide, I've seen more nefarious practices in years past. First, they will probably give you an option: you can either buy their modem for, say, $75, or rent theirs for $10 a month. In which case, it would depend on how long you were planning on being there as to which plan you'd go with.

What's more worrisome is that you will probably just be buying a modem, which is very necessary in connecting to the Internet, but very useless all by itself. I also connect my modem to a router, a wireless router at that, to keep my house wireless and I like the idea of a hardware firewall. Should you decide to go with a router, there are numerous ways to go about setting it up. I use WPA encryption with an impossibly long password full of lower, upper characters, numbers, and symbols, a masked SSID, and MAC address authentication. The 70 year old neighbors probably will never notice, but a Wardriver will.

Bottom line: I've just always suckered up and paid the telco for the modem. I guess I could take a stand and buy mine independently, but I just never have. If you do get their modem, and have a router you want to connect, and can't, you may need to bridge your modem to work with your router....but the above should get you going for now.