Hi Paul,
Thanks for your question about sniping Buy-It-Now (BIN) sniping.
There wouldn't be a service for this, because:
1. If you underbid, it converts the BIN listing into an auction, and you can snipe it as you would normally.
2. If you bid the same price, you could buy it outright. This is if the seller configures it this way.
3. If you overbid, eBay returns a message that you could buy it for less than your offer.
So the best strategy is to place a lowball bid like a penny, and then snipe it.
Thank you for taking the time to write in. Please let me know you need help with anything else.
bidslammer