Speaker purchase question

I have been a member here for 22 years, but encountered something today for the first time and would appreciate your opinions. 
I bought a pair of used speakers on Agon and they arrived with no grilles. The seller is stating that the pics did not have grilles (true) and they were not mentioned in the ad. These Rega speakers did come standard with grilles originally. I thought that the pics were taken to show the condition of the drivers. When I asked the seller, he said that he had looked into buying new grilles, but since he didn't mention them in the ad, it should have been obvious they weren't included. 
Am I wrong to feel deceived? I want to be reasonable and would be interested to hear other opinions. 

speaking from experience, not every buyer and seller here are noble characters, to say the least
I think that the seller should have mentioned that the grills were not included. Indeed, it seems that practice and precedent on the ’Gon is that grills are included in the sale unless specifically excluded.
Not entirely surprised

I've noticed in the last few years many speaker makers now offer grills as a billable option and not included as a feature

My initial reaction was this was sort of price gouging the customer to help increase revenue

Since I no longer have young children in the household, I typically park the grills in the corner and prefer to listen without them

My current thinking is pleased that the grills are an option and allows the speaker maker to charge me only for what I use

I've seen the cost for grills for towers range from $70-150 or approx 7% of the overall cost of a $2000 set of speakers

I like the idea of only be charged for what I use, like going the way of the ashtray in a new car.  Why should a nonsmoker have a cost included for something they do not use, while the smoker still has the option to add an ashtray.  Only the person that uses the part, pays to do so

That's a win-win imho
Your question is reasonable and some of the responses here are mean. You don't deserve that, OP. Amazing how even the most innocuous post can provide an opportunity for snark.

I think the seller could have been more forthright but that you don't have much reason to complain. If it were me, I might have put in a good rating, not the top one, and say something like (assuming it's all true),

"Speakers worked perfectly and were shipped on time and safely. Seller did not clearly disclose that grills would not be included and this is the reason I've left a less than top rating."

This would explain your rating, give credit where it's due, and yet warn other purchasers that this seller may need some coaxing to disclose all pertinent information. You may save a future buyer some headache or even some money.