That's unbelievable. If that's actually the case, then it calls for questioning. Why should any platform in crypto charge up to 12% as a transaction fees which is about 4x higher than what a traditional credit card payment platform could charge per transaction. Where does the charged fees go? To Ether or to SpiderDAO? I'm curious.
As this is a transaction on Ethereum blockchain, it is obvious that transaction fees will be paid to miners, which will be paid to validators in future. Now this is willingly paid by transaction issuer which does seem 4x of traditional card fees but you don't know about the ROI s/he is getting if he gets in. In order to get in, investor is not willing to take any chances of any failure. Now question comes to why would one pay such 12% tx fees willingly? I think you know the answer.
Risk is the reward in crypto space!