In the $20 range I also like the Titleist DT SoLo. I enjoy playing with vintage gear a lot, like the soft feel. I just picked up a dozen Wilson Duos, and they may be the equal of the Solo. I have only played about 18 with the Duo, but so far, so good. The Duo is especially soft feeling off the putter. I have tried a few of the e series Bridgestones, and haven't found one I like any better than the Solo. Bridgestone makes the Fix around $20/doz, which is advertised as being soft, so I may try a box of those.
My premium ball usage is mainly limited to tournaments and/or shambles, but I will play casual rounds with found ones. While I prefer Titleist over Bridgestone in low-mid priced balls, I go the other way in the premium lines. I have a slight preference for the Bridgestone 330 series over Pro V's, usually going with the 330 RX when I need or want a premium ball.
Even at my level, I can tell some difference in balls, but more so around the green than from the tee and fairway.