The thing is that this is just the pre-sale, and the packs will have the same prices when they come out on sale normally - and they can't even be opened in between either.

The whole point of a pre-sale like this is to reward your early & large investors - because once packs hit the normal store, it's a free for all.

If you have ~300 SPS, then you will most likely gain a full voucher ever 9-10 days, given the current totals. That's 3+ vouchers over the course of the airdrop. If you keep adding more, and claiming-staking often (compounding interest FTW), then it could be even faster/more.

Vouchers may end up with quite a premium, where your best bet could be to sell your 3-3.5 for $20 each or something, to buy more packs in the regular sale.