Well, kamihime is one of the most active projects on nutaku currently, you can often see it on number 1 place and it's barely ever outside of top 3.

Starting out right now means you are missing quite a lot of past events, some of which won't be repeated. Spending money on this game is very random - you may end up with nothing good even if you spend 1k $...

People usually reroll the account to get decent starting kamihime. After that it may be worth it to donate.. but if you don't get 1-2 SSR kamihime from your 6k starter crystals - just reset.
If you want tips on good kamihime to reroll to, then it's: Sol, Amaterasu, if you got sol then any light SSR kamihime is good to have as well.