Seller Blocking Me From Making Offers - Is He Being Unreasonable?

edweather - if you have capped bust halves for sale I will find you!

The best way to avoid low offers is for the seller to use the tools offered . You can set the lowest amount you will see and the rest are automatically declined. Then as a seller you can avoid any potentially obnoxious situations , either buyer or seller.
ebay is a very positive selling experience for us, I have been able to sell coins on the internet that would have sat forever in my shop or never even gotten a look at a table at a show.
Seller has every right in any any kind of establishment , store , online business, or restaurant to refuse service to anyone for any reason, so long as it does not violate a persons human rights. The right of a seller to block any bidder on ebay is
Perfectly OK. No reason at all is needed. Our blocked bidder list is not long but every name on there has earned a spot.

Pacificoin - Well said. There are some dealers who would be surprised if they had a 70% offer, but for the most part, don't even waste your time.

There is a way to see declined offers. When you go into your own listing, they are shown.
However, I can't see your logic. How are they potential customers?
A) Once an offer is declined you cannot accept it.
B) You should set your auto decline number to a level that you are sure you want to decline. If you may accept such an offer, don't auto decline it.

I have found the best way to deal with lowball offers is Not to reply to them and let the buyer just hang there until the offer expires.
They only get 3 shots at it and it is no skin off my back to just ignore them

I've actually had fairly decent success in making reasonable offers. Someone had a coin I wanted for 700 OBO. I checked the number,saw what PCGS price guice was and made a offer a few dollars higher then that. I think dealers also list some items high,just to be able to hear out and then counteract offers. I've actually been surprised a few times when the sellers accepted my offer. I guess if it doesn't happen,just move on and wait for the next score.

I've only been blocked by one seller. It was a coin listed at 35% over The NGC Krause world value and the listing described it as unique. I messaged asking to confirm the KM and what was "unique" about this one. His response was he didn't have time to look it up. I was going to make an offer based on everything (it was slabbed), but I'd already been blocked before I could even make an initial offer simply for asking those questions. Oh well. Life moves on.

In another instance, I messaged a seller about one of their coins. It would be a $90 catalog as problem free, but the coin had two planchet flaws (two broken edges). The seller listed it at $75. The value of the next grade down was $50. With the two flaws, I feel $50 is max valuation for its best day. In correspondence, the seller said they'd come down 20%, but that is $60. It's up to me if I want to pay a premium for this specific coin. It's still listed. But everyone was nice, and doors are still open for down the road.

But this past weekend I made an offer on an antique citrus crate from my family's home town. In the offer, I noted the reason for my interest and my reason for an offer that was 1/3 of his list price (what I've bought other similar crates for on ebay). I was s little surprised, but he accepted the offer :)

I think the nature of the beast is a few dealers don't actually want to be bothered, a few are playing capitalistic games more than anything, but the vast majority list a number as a starting point to good faith negotiations with someone and are accommodating from there to the back and forth as long as things are civil. I'm grateful the majority are this third type, and I'll not take offense with the minority others.