That "buyer" put that same message in the offer. "Can pay immediately." Okay? I in' expect you to.
If I needed the money, the items would be listed on niche sites with a lower price.
I have sometimes been criticized for listing at high prices, but I always have Best Offer enabled, and I have sold items for far more than people claim are worth. I once listed a deck for $1,000, it was posted in the "eBay listings by people on crack" thread. Got offers for $250 with messages like, "I bought a couple at this price it's not worth what you're asking". It sold for $700.
If you don't ask, in this case for a price, you'll never know the answer (or how high someone is willing to pay).