On a recent trip, I had a few hours free with my computer and no Internet. Out of curiosity, I wrote a script to simulate a few thousand opening turns given openings where you open Plan/X vs Silver/X.
I'm assuming a bunch of things here:
 You buy Plan turn 1, placing its Trashing token on an Action you buy turn 2.
 There are no Heirlooms.
 You don't get attacked.
 There are no Shelters (didn't want to simulate Overgrown Estate.
 On turns 3 and 4, you buy nothing. Depending on your opening, you may reshuffle before turn 4, and I didn't want to assume anything about what you buy on turn 3.
Obvious caveat: You don't buy Plan only because of what it does in the next two turns, you buy it because of the long term trashing you get to do. Given all these assumptions, idk how useful this data actually is, but it's sure a bunch of data!
Let me know if you see something interesting. Two things I noticed:
 Plan + Terminal Silver guarantees you hit $5 in the next two turns
 Plan + Poacher (or Tournament) is even more absurd of an opening than it sounds. Either you hit $5, or you hit $4 twice because you draw an Estate on turns 3 and 4. But in the 4/4 case, you just buy 2 Poachers to trash your last 2 Estates.
Silver + Terminal Silver
Money on turns 3/4  Probability  2/5  0.27%  2/6  2.53%  2/7  2.49%  3/4  1.26%  3/5  11.09%  3/6  12.66%  3/7  5.03%  4/4  7.59%  4/5  25.68%  4/6  15.23%  4/7  1.23%  5/5  11.73%  5/6  3.20% 
Hit exactly 0 $5+ hands: 8.85% Hit exactly 1 $5+ hand: 76.22% Hit exactly 2 $5+ hands: 14.93%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 35.34% Hit exactly 2 $4+ hands: 64.66%
 Plan + Terminal Silver
Money on turns 3/4  Probability  3/6  28.03%  4/5  71.97% 
Hit exactly 0 $5+ hands: 0.00% Hit exactly 1 $5+ hand: 100.00% Hit exactly 2 $5+ hands: 0.00%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 28.03% Hit exactly 2 $4+ hands: 71.97%

Silver + Terminal Copper
Money on turns 3/4  Probability  2/5  2.05%  2/6  5.07%  3/4  10.17%  3/5  24.07%  3/6  10.15%  4/4  17.66%  4/5  26.29%  4/6  2.57%  5/5  1.97% 
Hit exactly 0 $5+ hands: 27.83% Hit exactly 1 $5+ hand: 70.20% Hit exactly 2 $5+ hands: 1.97%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 51.51% Hit exactly 2 $4+ hands: 48.49%
 Plan + Terminal Copper
Money on turns 3/4  Probability  3/5  44.61%  4/4  55.39% 
Hit exactly 0 $5+ hands: 55.39% Hit exactly 1 $5+ hand: 44.61% Hit exactly 2 $5+ hands: 0.00%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 44.61% Hit exactly 2 $4+ hands: 55.39%

Silver + Terminal Giving $0
Money on turns 3/4  Probability  1/5  0.52%  1/6  1.25%  2/4  4.99%  2/5  11.31%  2/6  5.00%  3/3  5.15%  3/4  25.12%  3/5  22.37%  3/6  2.60%  4/4  15.15%  4/5  6.55% 
Hit exactly 0 $5+ hands: 50.41% Hit exactly 1 $5+ hand: 49.59% Hit exactly 2 $5+ hands: 0.00%
Hit exactly 0 $4+ hands: 5.15% Hit exactly 1 $4+ hand: 73.16% Hit exactly 2 $4+ hands: 21.70%
 Plan + Terminal Giving $0
Money on turns 3/4  Probability  2/5  16.77%  3/4  83.23% 
Hit exactly 0 $5+ hands: 83.23% Hit exactly 1 $5+ hand: 16.77% Hit exactly 2 $5+ hands: 0.00%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 100.00% Hit exactly 2 $4+ hands: 0.00%

Silver + Poacher
Money on turns 3/4  Probability  2/5  0.24%  2/6  1.96%  2/7  3.16%  3/4  1.28%  3/5  9.42%  3/6  18.17%  3/7  3.15%  4/4  6.78%  4/5  36.26%  4/6  11.52%  5/5  8.07% 
Hit exactly 0 $5+ hands: 8.06% Hit exactly 1 $5+ hand: 83.87% Hit exactly 2 $5+ hands: 8.07%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 37.38% Hit exactly 2 $4+ hands: 62.62%
 Plan + Poacher
Money on turns 3/4  Probability  3/5  10.14%  3/6  15.30%  4/4  10.19%  4/5  57.89%  4/6  2.75%  5/5  3.72% 
Hit exactly 0 $5+ hands: 10.19% Hit exactly 1 $5+ hand: 86.09% Hit exactly 2 $5+ hands: 3.72%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 25.45% Hit exactly 2 $4+ hands: 74.56%

Silver + Smithy
Money on turns 3/4  Probability  2/5  0.26%  2/6  1.29%  2/7  2.14%  2/8  1.39%  3/4  1.28%  3/5  5.58%  3/6  9.04%  3/7  10.88%  3/8  0.25%  4/4  3.82%  4/5  14.76%  4/6  23.38%  4/7  2.73%  4/8  0.14%  5/5  14.52%  5/6  6.24%  5/7  0.88%  5/8  0.09%  6/6  0.76%  6/7  0.57% 
Hit exactly 0 $5+ hands: 5.10% Hit exactly 1 $5+ hand: 71.83% Hit exactly 2 $5+ hands: 23.07%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 32.11% Hit exactly 2 $4+ hands: 67.89%
 Plan + Smithy
Money on turns 3/4  Probability  3/5  6.72%  3/6  13.53%  3/7  2.19%  4/5  26.99%  4/6  18.09%  5/5  18.91%  5/6  10.42%  5/7  1.05%  6/6  2.10% 
Hit exactly 0 $5+ hands: 0.00% Hit exactly 1 $5+ hand: 67.52% Hit exactly 2 $5+ hands: 32.48%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 22.44% Hit exactly 2 $4+ hands: 77.56%

Silver + Terminal Giving +2 Cards
Money on turns 3/4  Probability  2/5  0.24%  2/6  1.24%  2/7  3.85%  3/4  1.25%  3/5  5.60%  3/6  27.79%  4/4  3.81%  4/5  56.23% 
Hit exactly 0 $5+ hands: 5.06% Hit exactly 1 $5+ hand: 94.94% Hit exactly 2 $5+ hands: 0.00%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 39.97% Hit exactly 2 $4+ hands: 60.03%
 Plan + Terminal Giving +2 Cards
Money on turns 3/4  Probability  3/4  2.36%  3/5  14.18%  3/6  7.22%  4/4  20.30%  4/5  49.92%  4/6  2.40%  5/5  3.62% 
Hit exactly 0 $5+ hands: 22.66% Hit exactly 1 $5+ hand: 73.72% Hit exactly 2 $5+ hands: 3.62%
Hit exactly 0 $4+ hands: 0.00% Hit exactly 1 $4+ hand: 23.76% Hit exactly 2 $4+ hands: 76.24%

Code is at
https://pastebin.com/YCexJ5A2