Put those games in your want list and go into your trade section and select direct trade. Or, you could search each of those games and find people in your area who are trading. All of this takes work, but I've had some great success with it.
But, like I said before, everyone wants to trade up but you have to be fair. Yes, sometimes you can trade up, because the value of the game is personal to most people. However, the majority of users will not trade away a game for another game that has a 20$ difference in price. Find the sweet spot and be polite when messaging people.
What I like to do is trade a game with money. If I want Galaxy Trucker and it's retail value is 60 and I'm trading Race for the Galaxy, I'll find people who want my game who have my wish list game and I'll offer them both the game and 25 bucks so I cover the difference.