The DP720 offers a portable DECT 6.0 phone with DP750 IP Base Station. This is a great entry level cordless solution. The DP750 base station can control up to 4 additional DP720 handsets (sold seperately)
 
This is a very good lower cost wireless solution.
additional handsets for the base station are inexpensive.
 
However if you have a larger location with good wifi the WP820 cordless may be a better option.