I plugged your numbers into the excel spreadsheet I use to manage my AIM portfolio. It has a bunch of tweaks that I have discussed over on SI in the past. Using my standard set of parameters that I use for almost all my stocks (not mutual funds) I get the following. I did not tune this at all. Just took five minutes to paste the price history into my a worksheet template. and then a little time to format the results for the post.
Start with $20,000, 30% cash. Buy/Sell = 10%/10%
week shrs price
1 Buy 140 @ 100
4 Sell 17 @ 129
12 Buy 20 @ 90
13 Buy 41 @ 75
14 Buy 32 @ 70
24 Sell 21 @ 95
26 Sell 17 @ 104
31 Sell 16 @ 114
45 Buy 25 @ 81
48 Buy 27 @ 75
53 Buy 21 @ 73
69 Sell 21 @ 97
76 Sell 23 @ 109
Port Control: $18,463
Cash: $ 5,747
Value: $24,847
It doesn't beat your numbers, but I feel pretty good about how close my standard tweaks came.