Refreshing Impulse Points

[FishDude]

GURPS Power-Ups 5 discusses "Impulse Points" (a pool of character points for impulse buys) and how much they should cost if they recharge. The cost is pretty clearly 5 points/level if they recharge at a rate of 1 per session. If they recharge at a higher rate, then there is a further cost of 10 points per additional IP recharged per session. However, the math here is a bit ambiguous: If I have a pool of 3 IP that can recharge fully each session, is the price:

(5 * 3) + 20 = 35 points

or

(5 + 20) * 3 = 75 points?

[Varyon]

I'd interpret it as the first - Impulse Regen costs [10] per +1 to the per-session regeneration rate. Note this is stated as the minimum cost, with the implication that GM's may see it as appropriate to charge more.