Since this is dev.....and not taking the license into consideration.
You can have multiple HANA DB installs on one appliance. The key is to set your global_allocation_limit on each instance accordingly.
For example, if you have a 1TB box and will install 3 instances. You'd set the global_allocation_limit to 256GBs on each instance. You may room for another 128GB instance. Remember to leave at least 10% for OS and other processes.
1681092 - Multiple SAP HANA databases on one SAP HANA system
1661202 - Support for multiple applications on SAP HANA
Also, check admin guide.