Yes, it is definitely a problem because you can get into strife whatever you do.

A non reply can look rude, but then, who asked them to make this "offer" in the first place?

Non of my items have "Make An Offer" on them.

I don't do business that way and don't appreciate unsolicited offers on already competitively priced items.

Some sellers do have "Make An Offer" and each to their own, but the price I put is the minimum I want, taking into account the costs of selling, tax and postage.

If the item doesn't sell, I will often drop the price or list it elsewhere than eBay...

Adding them to the BBL list is probably a bit harsh, although I have sometimes done this with people who persistently make very low offers..

"Make an Offer" causes confusion as to the value of the item and I cannot see any benefit in stringing out the process of buying any further than is necessary..

However, it probably works for some sellers, with buyers who have the perception they are getting a bargain...