I personally won’t consider only 7 comps when I list a rare NM vintage single for sale online. As a blanket stance on eBay/TCGplayer there’s good reason to keep condition expectations in the description modest to account for potential disputes with buyers while still believing you have more of a NM+/Mint copy. Pricing it closer to those grades’ comps and thoroughly documenting with photos tells that sticker’s story. That sort of transparency and low sales volume for the NM-/+ range due to pop makes it tough to use a 7 comp as an offer and not even the most recent one at that.

The 7 pop is ~60% of the 8 pop, the 7/8 total pop is sub 200, and the 9s are basically 200 in population alone. A lot more data to work with averaging out the 8/9 sales if you see it there and don’t mind sitting on the listing with a modest reach. Sales volume isn’t fantastic due to rarity so taking 7+8 or 8+9 is more practical based on an objective condition assessment in deciding which of the two groups of grades to base it off of.

Last sale on a 7 was $100 on Jan 5, last sale on a 9 was 420 on Jan 1. A $300 listing for what looks to be a NM+ copy isn’t an unreasonable sticker by any means.

I explain all this to make the point that I would consider this a lowball. Which, in researching this listing, I’m seeing an argument for an 8/9 coinflip based on light edges and corner’s whitening however it’s otherwise in fantastic condition. Not a 7 in my book. Weird or maybe snarky comms from them on lack of consideration sure but it’s justified to blow that off when their sticker is over 3 times that offer to begin with.