No matter how many alts you have, you just contribute with your main... besides, gold contributions - in the HKoA - were meant exclusively to the 50+ toons and wasn’t an obligation.
However, if the player doesn’t want to support the guild bank he won’t be able to access it.

We used to raid everything together, the BoE items not needed for any of the part members were sent to the guild bank.

If we solo any low instances such as VC, SFK, SM (or pick a few lowbies, since there are nice BoP gear) once a week we can collect items in benefit of the players below level 40.

The crusader plan idea, in my opinion, doesn’t work (i.e.: it sells for 200gp... you can’t stay 40 weeks without contributing), the bank needs money to maintain itself and support the guild.

The money from items sold in AH and the small raids in lower instances will be our contribution to help our lowbies.

While HKoA GM, I never used the bank myself, but many of my ex-guildies got a few of their tier 1 set from the bank. I’m pretty sure as soon as people start seeing the benefits the idea will be easily accepted.

I can’t imagine a guild bank without $ (in fact a bank = money in my conception) ... unless we wait enough time (months, maybe year) to get enough money in AH from unclaimed items.

Level 35-49 members will support helping the lowbies in minor instances (a 49 pally/warrior/druid) can easily solo VC, SFK etc... and/or help a group of 20ish in deadmines.

This system worked in the HKoA because we’ve decided to become an end-game guild. The knights, as whole, did not work due to some players’ immaturity and other problems but the bank was a great success.

While Aldrwin, my level 39 mage, is not a level 50+, I will be glad to support the guild with weekly gold and blue donations from our TG raids that I play with Sacredlord.