Ok, now I am at a computer I will give my true take on this:
If someone doesn't list prices in their thread, then any enquiries that they receive asking for a price could well be time wasters. but it is your own fault!
Now, if I have a card that sells for $100 on eBay, then someone messages me and asks for a price, I offer it to them for $80 and the person says "no thanks", then yes, I feel that is lowballing. You don't have to make an offer to be lowballing, if you turn down a price that is more than fair, then that is still lowballing because you are essentially saying that is too high for me. Either that, or you were never really planning to buy the card.
As far as people that do lowball?? Who cares!?? I do it sometimes too! So what??
Dave (Aussielaker) will testify to this too! He had a Derrick Rose auto FS last week. I was not really in the market for a Rose auto, but I always like to pick up tradebait to help me get PC cards of people who don't sell. Seeing as I am not particularly fussed on a Rose, I offer $200. I know that card should be able to get $250, but I am not wanting to pay full eBay for it. If I was, then I would have bought one off eBay.
So, Dave calls me a tightarse, but in a polite way coz that is the guy he is, so I increase my offer a bit to a figure we are both happy with.
We also need to look at the whole "value" argument.
If I have a card that recently sold on eBay for $300 then I list it on OzCards for $300, then I should EXPECT, at maximum, to get $270ish for that card on here. The buyer is doing me a favour by allowing me to avoid eBay fees, as well as reduce the risk of paypal claims/lost cards. But people here list their cards at full eBay and when any offer comes in lower, they get upset??
I have really enjoyed my collecting habits over the last few months because of one thing. I have stopped looking at ANY cards as being 'must have' cards. I used to get sucked into paying top dollar for a rare Kawhi or Blair because someone on eBay is greedy or whatever, but now, if I don't think a card is genuinely worth the price, then I don't want it! Simple!
By collecting HOF on card autos, the options are endless and I am never held for ransome because there is always another card to spend my money on, that way I never have to worry about getting in bidding wars for cards, or getting upset about missing a particular card!
Life is too short and this is a hobby, not a necessity!
/Wisdom shared! I'm out!
I hate offering. I always push for a price, cause I do not want to lowball. I then decline if the price is out of my range 
