A great place to look is eBay's sold listings (to) compare your collection against what is selling." There is a number of prominent websites that offer guides to loosely grade cards yourself too, while information on rarity is readily available online.
There is a deliberate visual continuity between this card and its Base Set ancestor, and the 151 set was explicitly designed to capitalize on that connection: every original Kanto Pokemon received new cards, and the Special Illustration Rares were positioned as the ultimate chase pulls for each Pokemon
BPhillipYork: I think this is a totally cool trigger
If you have no follow-up card draw, you might have to eschew Brigette and dig through your deck with draw Supporters
Good interaction in general, but a deck like this is going to be able to get up to enough to kick it fairly often
For example, Bloodstained Mire can fetch Jetmir's Garden, which gives you red and green but also that touch of white when you need it