dCity is awesome but I have never played Splinterlands and I truly can't get the attraction of Rising Star except I just cream off a few tokens a day I'm a little ashamed to say!
If you're thinking of getting into dCity, the prices on the market are a fraction of what they were and you can build a nice city for peanuts! Give it a go and of you need any help or advice, hit me up :-)
Someone suggested to build your Rising Star account up to Level 20 and then start pulling 50% of your Startbits off to buy SIM for your dCity. I think I may use this strategy once I get there.