I don't believe there is, and unless you plan on buying the entirety of your wish list in the next 3 or so months, I doubt it would help you. Prices change all the time. I cannot tell you how many times I've waited on a game becuase 'it's cheap, I'll get it later'- and then it isn't anymore. Solatorobo is the big one off the top of my head- MONTHS I saw that sittin' around $25-30, waiting to see if it dropped below $20. Then it was gone. Then it was decidedly NOT $30 anymore.
Similarly, you never know when a deal's gonna come smack you in the face either. I was once at a game store doing a big clearance- let's get rid of ALL games older than PS2 (This was awhile ago), $5 bucks each, we don't care. You know what I found with the stack of disc-only PS1 games? Suikoden 2. I wouldn't let go of it at the counter so they couldn't change their minds, I just held it out to be scanned. I've watched the prices of Final Fantasy 7 and Disgaea bounce up and down like a basketball.
I'd probably just focus on how much a month you can comfortably devote to games, and price titles in small groups as you prepare to buy them. You'll be better equipped for price changes, or just changing interest in a title.
