Well, not quite top-30. By my count his $12.5M per year is tied with one other contract for 40th among outstanding contracts (contracts for next season at least) in terms of dollars per year over the lifetime. There are another 16 outstanding contracts worth at least $10M per year, for a total of 57 contracts either bigger or within sniffing distance. So, at this point your average team has two guys in the Tony Parker price range. We don't have any, so it's reasonable to think we can afford him.
If you look at advanced stats (which I know you hate, but here you go anyway) Parker was 27th in Win Shares and 26th in PER among players with 1500+ minutes last year, so he may be outperforming that salary a little. Among PGs he was 5th in points per game, 15th in assists per game, 8th in TS% and 1st in FG%.
The thing is, we know who Tony Parker is. He's a proven commodity. He's a veteran in the prime of his career, a three-time All-Star, and if anything it looks to me like he's just a little bit underpaid right now. We have money to spend, and we can afford him. Presumably as the salary cap drops over the next few years his contract will be a bit less palatable, but as it stands right now with Parker in the wing and without sending off a contract like Beno to counter his money, we would be at the following salary levels:
2011-2012: $40M for 9 players (Evans, Cousins, Parker, Beno, Cisco, Thompson, Casspi, Greene, Whiteside)
2012-2013: $38M for 7 players (Evans, Cousins, Parker, Beno, Cisco, Casspi, Whiteside)
2013-2014: $18M for 3 players (Cousins, Parker, Whiteside)
Everybody else that we would sign to fill out the roster for now and the future would be signed under the new CBA rules where we would still have a decent advantage over most teams in cap space and would of course be smaller deals than we are used to now (by, what, maybe 30%?). We can totally survive Parker's contract if we trade for him, and things only look better if we can strongarm the Spurs into taking Beno back (or find a third team to shift Beno's deal to if Pop refuses Beno for personal reasons). I think he's worth the gamble at this point. Unless we really love a guy at #7 (somehow I don't see Fredette or Leonard leading us to the playoffs next year, but Parker, yes) or we see a better way to spend the money, I think we have to go for it.