Strips are known to be unreliable .
Liquid is worth the cost. Just order the API master kit online and it is reasonable.
As for automatic test Hanna makes great test for particular parameters. Mostly reefers use the hanna stuff but a freshy could use some of them.
If your tank is not cycled I think you basically need a test kit.
If your tank is cycled and well established you may get by fine without ,but if your fish are trying to tell you something and you don't get it you will wish you had a kit IMO
The kit is handy to establish a 'baseline' of your water parameters and find out how it changes after you add it to your system.