Insulting potential buyers isn't a great way to go about getting sales.

Note that the over riding rule in the DP list of regulations is CAVEAT EMPTOR. If you don't get any people wanting to buy from you Kirbz, it will be due to payment options. You might have to wait, get a Paypal account, or ask your parents.

I'm going to leave this open as technically there is nothing wrong per se happening, but I suspect because this isn't the 1990s any more, you won't get any buyers without some way for them to ensure you have definitely got the money and claim "it never arrived"...