This timer assembly has been listed on eBay several times in recent months with no takers. For starters I think the seller's asking too much, but he'd also likely do better to separate the timer, dial, knob, and center cap into different auctions. Since this is the center cap you need, you might try suggesting that to him and make him an offer for just that part. Then again the knob is in really good shape as well, so you may want to try to pick that up as a spare.