mmm, don't know. let's do a hypothetical, say you receive 1200 bitcoin. you give back 400 in some token.
                         that leaves you 800 bitcoin which was given to you to buy back 400 over time. (i gotta start me 1 of
                         these gigs.) i think a better way would be to distribute 100% (less costs) token back to investors and                                                                               
                         then have investors donate to your fund. build a better community spirit perhaps. hope it works out well                                                                                                                                                                                       
                         for you, but not enough info for me. i could be wrong, wouldn't be the first time.