Alternative investment track with exponential returns as you spend more.
6 rounds on the image, so you need to pick which adjacent set of 4 you want to use. The top four are very gentle, allowing you to save more money for later, the bottom four make for a much harsher game, leaving slim pickings by the last round.
Potential variant - you MUST use ALL of your investment cubes if possible (2 per box rule stands...?) so IF by the last round you have £5, then sorry, you bought a bad investment and lose 10 VP! probably works best with suggestions elsewhere of only having 8 investment cubes.