If you have the MagicJack VOIP service, you must connect to the internet at home to use it, right? You could just add a $20 wifi dongle to your computer and you'll have free wifi. I've been using 2 of
these by TP-Link on 2 computers when I switched to AT&T Uverse (so I could dump the landline) and didn't need my wifi router anymore. They're both over 4 years old now and never a problem with them.
I do have them on USB extension cords moved closer to where I need them, and leave them sort of hanging free so air circulates around them better. They can heat up a bit, so I just did that as a precaution. And the 2 PCs I use them on are WinXP machines, so there's no problem there either. I really didn't expect them to last long, but they've been surprisingly fine and one is in use 24/7, the other not as often.
Edit: You might double check that your existing modem/router (often a single combo unit now) isn't also capable of wifi. Quite a few of them do at this point as standard issue.