Here's the dilemma. That old landline number - people all over have had it for years. Some calls still come through because that is the number that people have. And for those times when you leave the cell phone in the car - or the battery gets too low, there is a phone number works in the home. Some people want a functioning phone line in the home at all times if there are children present.
Many people simply ditch the landline. Anybody calling that number will get an error message until your old phone number is reassigned to somebody else. But there are a few strategies where you can retain a home phone number without that large monthly expense.
1) Republic Wireless uses either the Sprint network or your wifi system to make calls. If you use wifi only the cost is only $5 per month You need to have a Republic phone. They sell them starting at $129. If you also use it as a cell phone away from your wifi, the monthly cost is $10 per month plus $15/gig for cellular data.
2) Project Fi is another plan that uses wifi calling, but it does not include an option for wifi only at a lower cost. The basic monthly charge for Project Fi is $20 per month, plus $10/gig of data. Project Fi is owned by Google, with cell service by Sprint or TMobile. You have to use a phone that is compatible with Project Fi, such as the Nexus 5X or 6. Project Fi has international capabilities, including reasonably priced international data.
3) Cricket Wireless might be an option to consider if you have several lines on a plan. Adding a 4th line costs $10 more per month than a 3 line plan. If you already have 4 phones on Cricket, the 5th line is currently no additional monthly charge. (4 lines OR 5 lines cost a total of $100 per month) Cricket uses ATT cellular towers. Phones need to be GSM phones, the type used with ATT or TMobile.
If you have cordless handsets with bluetooth capability, you can have extensions that ring at different parts of your home. Initial costs of the cordless phones and the cell phone might add up to several months of landline bill. But then your monthly costs are extremely affordable. Plus when you travel, you can take your new "landline" phone with you. In the case of Republic and Project Fi, those phones can be used so long as you have a wifi connection.
So if you have considered ditching the landline, but hesitated, there might be a third option to have a phone that rings in the home without the large expense of a traditional landline.