Ok, I have not had a vcp subscription for some time, so if they have some stupid "on the rise" arrow like beckett, etc. than so be it. But let's keep this simple based on one of your listings, this one:
1962 Topps Mantle Switch Hitter PSA 5
This card has also been on the rise with the last 5 sales averaging $47.40 VCP.
4/21/17 eBay BIN danielaaronlee $50.00
3/8/17 eBay Best Offer chessdad3 $40.00
2/1/17 eBay probstein123 $56.01
1/21/17 eBay tripleplayvintagestore $41.00
1/18/17 eBay 4_sharp_corners $49.99
According to this data, in January this card sold for $49.99, and one recently sold in April for $50.00. (and of the three in between 2/3 sold for less). So based on your listing, this card is on the rise! One whole penny! Do you see what I am saying? Don't take this personally, I just don't like when misinformation intended or not is used to make a sale!
In fact, if I were to use your logic/math I would have to sadly say this card is in a small decline
LOL