wow, must be a beautiful card. very jealous....
my sources for value-ing a card are SMR, eBay (both completed listings as well as what's posted for sale -- and therefore hasn't actually sold yet), and VCP (keeping in mind that VCP misses many eBay auctions).
VCP reports no sales of the Chase white cap in that grade. They only recorded one PSA 7 that went for nearly $1700 is 2006, but one sale from 4 years ago (ie pre-recession) I'd find highly unreliable to go by, plus at that high a grade there's not always equivalence between third-party graders.
Hope that helps,
--S