Off the top of my head and with very little sleep, the only thing I can think of is if you have the potential buyer(s) contact you (via email, etc.) to arrange the purchase. As far as I know, the only way to keep inventory straight on a freestanding/personal website is to have a "shopping cart" that allows instant purchasing and removes the item from inventory. You may lose business doing it that way since you will be adding "time" between communications. I am a huge online shopper - but if I have to call or email someone and wait, I will most likely not end up purchasing the item(s). I think it's worth etsy's fees to save yourself time and work. You can still use your web address - just redirect it to your etsy store URL. So, when people type your web address in, it automatically forwards to your etsy store. That's what I did!