Have Rubinas...and Rubinas>>>Echidna...
Will think of Echidna only after i get Anya ready...

Also i highly recommend everyone to get the time fairy if not Dorania+Time fairy....
Time fairy gives a 100% cost reduction always...and you can get only 1~2 every year...

Only getting Dorania and not the time fairy is just a waste...coz Dorania is useless if not changed into Anya...

Also its pointless to get Aria other than collection purpose...coz...liz>>>Aria/Katie...

Hence,
Time Fairy>Dorania>>>>Echidna>>>>>>Aria...