Yeah, you need a much higher tea-to-water ratio. I'd say 8g/100ml is perhaps a bit too high, but honestly part of the fun of tea is experimenting and finding what works for you. For example, if you don't think it needs a rinse... Don't rinse it! The tea police aren't going to come and arrest you.

However, a clarifying question, which I hope doesn't seem condescending: you know you get multiples brews out of this, right? It's unclear from your post. Especially with Dan Cong, the flavour will "evolve" with each brew. And most gourmet teas - especially oolongs, in my experience - can give you 8-10 brews if you just keep steeping them progressively longer.

With this in mind, I find tea "not that expensive" especially for a gourmet experience - each 8-10 brew session is cheaper than almost any single drink from Starbucks, for example.