Thank you for asking this thought-provoking question, so this is what I would do with an extra $100 to use to grow my SFI business... I would buy 200 TCredits for $63.80 and 20 TCredits for $10.12....(100-73.92= 26.08) giving me 2000 Sales VP.
The remaining $26.08 I would save to pay for my future PB Auction wins.
An "extra" $100 could be used to advance with Action VP for bids, at the right time.