Moral Hazards and Dealers

One of my favorite pastimes recently is to hit dealers that may have not updated their prices with the current rise in silver. Most dealers have done a decent job in doing so, but foreign stuff does not seem to be paid attention to and with different purities, dealers either dont know or dont care.
I have been able to hit 90% at 15-18x face at antique stores and some great deals for foreign silver. But by now most dealers have gotten with it. What is your feelings on this topic. Like at a coin shop I found a proof 1964 quarter clearly marked $4. I informed him and he quickly took it out. But he would have honored it if I would have pressed him. I mean if you have been dealer for XX years, with a store front, with $1400 krugers and $500 Carson city dollars staring back at me is it your job too tell them or take the money and run.
As an example at a coin show today I bought these from a dealer who has been then there for at least 10 years:
1960 Canadian Dollar $7
1964 Canadian dollar $16
1890 Morgan Dollar $20
1922 Peace dollar $16
1935-S Morgan $18
and two barber halves for $8 each
He honored the prices- but would you feel bad? Would you have told him and walked off? It goes to show no one was looking at his stuff anyways- he couldnt even sell a $7 Canadian dollar!
(there was about 15 dealers at this show as well BUYING morgans for $20 each, 90%, etc.)
This was at 1 pm, 3 hours after the show opened. It goes to show in a place like Michigan ppl dont look or cant afford deals. Found a butt load of 92.5% Can Dimes for $1.50 each. Went to a local coin shop afterwards and found 1960 Mint sets of Canadian Coin ($1.85 Face of 80%) for 12x. The dealer first said they were put out 'last week' and when I got them out of his case to buy them he looked and said 'looks like these are priced under melt- you arent supposed to buy these!' but he honored it anyways, even thought silver was likely $27-30 last week and does not warrant 12x anyways.
So what is your feeling on the topic? Rob them blind, tell them, please share!
I have been able to hit 90% at 15-18x face at antique stores and some great deals for foreign silver. But by now most dealers have gotten with it. What is your feelings on this topic. Like at a coin shop I found a proof 1964 quarter clearly marked $4. I informed him and he quickly took it out. But he would have honored it if I would have pressed him. I mean if you have been dealer for XX years, with a store front, with $1400 krugers and $500 Carson city dollars staring back at me is it your job too tell them or take the money and run.
As an example at a coin show today I bought these from a dealer who has been then there for at least 10 years:
1960 Canadian Dollar $7
1964 Canadian dollar $16
1890 Morgan Dollar $20
1922 Peace dollar $16
1935-S Morgan $18
and two barber halves for $8 each
He honored the prices- but would you feel bad? Would you have told him and walked off? It goes to show no one was looking at his stuff anyways- he couldnt even sell a $7 Canadian dollar!
(there was about 15 dealers at this show as well BUYING morgans for $20 each, 90%, etc.)
This was at 1 pm, 3 hours after the show opened. It goes to show in a place like Michigan ppl dont look or cant afford deals. Found a butt load of 92.5% Can Dimes for $1.50 each. Went to a local coin shop afterwards and found 1960 Mint sets of Canadian Coin ($1.85 Face of 80%) for 12x. The dealer first said they were put out 'last week' and when I got them out of his case to buy them he looked and said 'looks like these are priced under melt- you arent supposed to buy these!' but he honored it anyways, even thought silver was likely $27-30 last week and does not warrant 12x anyways.
So what is your feeling on the topic? Rob them blind, tell them, please share!