I like your strategy, and you could maybe get him...but I don't think it's a good risk/reward scenario for you. That C- will be just too inviting for better schools to battle you. And if you miss out on him, what are you left with then? Even if you get him, what about the other pieces around him. If you're dead set on going after him, I'd do one of the following:
1. Start with 35k into him. If you see an A-school on him from the start, I think you're in trouble and may want to reconsider your all-in approach.
2. Start with 50-60k and cross your fingers you don't need to spend the other 30-40k.
The money you hold back upfront can always be earmarked for this guy if you're dead set on battling, but keep a reserve in case you want to change course or you see some other desirable kids you want to go after.
Also, don't go w/30 mins. In case you get him, you will likely have problems getting him those minutes. You could probably accomplish your goal just as well with 15 or 20 mins.
If you follow through with this, update this thread. I'm curious to see how this strategy goes for you. If there's no update, I'll just assume you swung and missed on him ;)