Topps Chrome are high volume cards, short prints and autographs are very rare.
Even though this Card is numbered to 399, due to the larger volume of base prints (base prints can run upwards of 200,000 cards) this creates a ton of cards locked away in boxes that will never be discovered, many Card vendors hoard hobby boxes for years and then ask a high cost (sometimes 30x retail) due to the boxes being harder to find. This creates what Beckett (the company considered the Card authority on authentication, grading and pricing of the cards) Population. Card Population is what is known to be out available in the market and not in a hobby box or private collection.
This card Population on this card is beyond low due to the fact it is an alternate rookie card "Freshest Rookies" and a numbered Refractor to 399.