Penthouses at Trump Park Avenue don't have the best sales luck. There was PH29, which took two years to sell at a $2 million loss. Then there's ad man Donny Deutsch's penthouse, still on the market for $25 million after a sizable PriceChopper. But 502 Park's PH21 won't let a little thing like neighbors' sales failures get in the way of its dreams. The 7BR, 8BA, 7,132-square-foot apartment, pictured above, has been on the market since May, when it first asked $22.5 million. (It's also available for rent at $65,000/month and spent a little time on the sales market in 2010 for $22.5M.) Late in May, it increased its price tag by a modest 11 percent, to $25 million. Then came the really gutsy move. As of yesterday, the penthouse is asking a whopping $35 million, a PriceUpper of 40 percent. Don't think it's worth that price? Talk to the hand.