I echo these sentiments, a partial payment to start with (% based) would give reassurence on receiving the remainder at some future date. Personally, if this future date is a while in the future I am ok with that, I realise others' situations vary. I think at this point no one is thinking about the interest just in getting back what they put in initially in good faith. Also, I don't know if you are currently holding BTC or fiat but if holding fiat with the intent to purchase BTC then there is the risk BTC rises in the meantime (likely imo) then it is going to be even more difficult to honour the initial BTC investments. Either way, appreciate your honesty even if the current situation is less than ideal.