The first question, do you have an existing contract with Nextel? If so, when is it up? If you are still under contract, (depending upon the terms), it could be costly to cancel or downgrade service.
Second question, when you say “two-way paging system”, are you talking about pagers with two way text messaging?
I have found that conversing via a two way pager is cumbersome when trying to conduct business.
A couple thoughts:
If you really rely upon the push to talk feature of Nextel, other carriers offer this option now. Verizon offers a push to talk service, and Sprint has the “Ready Link” service available in most areas. They both have bundled feature rate packages available to the average consumer. They are worth a look. We tested both Verizon PTT and Sprint Ready Link, and found both to be usable. There is a notable difference to Nextel, mainly delay on initial call setup. After the initial call setup, the quality is great. The coverage is better on the Sprint/Verizon options because Nextel is pretty much limited to the metropolitan areas. You get a few miles off a major roadway and you loose the Nextel signal.
I would talk to a business rep from each carrier, and have them quote services to you based upon your typical usage patterns. You may find that you get a better rate from a cell/PCS carrier with PTT features in a pool plan. Pool plans are sometimes the way to go when you have several users with different usage patterns.
One thing to keep in mind, there may be some interesting marketing changes around the bend since Sprint announced their purchase/merger with Nextel. There is no telling what this will do to the offerings from either carrier.