Actually, you can lose battles to DII schools with high prestige who are REALLY, REALLY into a player you're going after. I currently have had two seasons of recruiting with D- prestige at DI under my belt, and I have to say you'll be lucky to sign a 1 star player, and a 2 star player is a major reach (but not an impossibility). Go for the guys with good potential. Look for guys with solid cores but low durability. Be willing to take some sacrifices (take a big with 80 ath, 70 reb [high potential], 70 blk [high potential], but 30 per [average potential]. You don't need to necessarily avoid battles with other low tier DI schools (I beat out a C prestige DI school to sign one of my most recent players), but NEVER battle with a team from a power conference unless they have equally terrible prestige. Knocking off sims isn't all that hard to do either, but just be weary.
UTILIZE FSS AS MUCH AS POSSIBLE. Focus on players with high potential, and make sure your list is nice and long, because some of your targets are bound to get gobbled up by higher prestige schools. Never give up on your best targets though, because it's possible an elite school has him on their list as a backup option. The second they drop him, he could become fair game, and you could potentially land a gem.
Recruiting with D- prestige is tough, but you can certainly still gather a solid class if you're careful and smart.