There is already a challenge exactly like the one you're describing called "Cactus Farmer" where you give 64 cacti and get 1 sand, and it is repeatable.

Assuming you know about the above (And if you don't then ignore this); then if you're suggesting introducing another cacti challenge for "larger amounts of cacti" (I'm assuming you mean something like 640-1000 cactus for 10 sand) then I don't really see a point for it. Blocks like sand aren't supposed to be easy to get and cactus is very easy to obtain in large amounts hence why it has no value on main server. If the above challenge was implemented it would basically be like saying "Here have 1000 free sand".

TLDR: There's a reason cactus doesn't have a lot of different uses on skyblock, and that's because it's so easy to get/you get so much of it with literally 0 effort.

 

but why? if you make cacti worth nothing then you can't really do anything useful with sand.

 

In Batch'n'Go, there's already a challenge that requires 640 cactus and gives you 10 sand if that's what you were looking for.

 

I remeber Andrew trying to get opinions on something similar to this suggestion. He wanted to know if it was worth bumping the price of cactus up to $0.01.

I think finding another use for cactus would be good... as right now, after you do the cactus and dye challenges, there really is no use for cactus outside of using it to kill slimes (which only takes a couple cactus). I know that after I completed the challenges where cactus was useful, I’ve had nothing to do with my cactus. I can’t think of any other way it could be useful so it would be nice if I got a penny for selling it.

As for this suggestion, others have already said it, we have a couple challenges that take cactus and gives you sand. We also have a green dye one that gives you iron nuggets. I don’t see a point in yet another challenge because once you do it the 100 times limit, it will render cactus useless again. If Andrew is ok with making cactus sell for a penny, I think that’s the best option.

 

That works by setting the item value to $0.005. For example, dirt already uses that value.

 

Bumping with a note to myself to look into infinite cactus challenges as well.

 

Am I the only one on skyblock that would love to make more glass? :D
I absolutely don't want to farm on skyblock, but I would still love to have cactus, as well as potatoes, carrots and other crops, at least worth something.
It hurts my feelings to work for something and it to have zero value, but I am an old man :roflmao:

 

-edit-
Was already mentioned oops.

 

Novice - Cactus Farmer (Max 100 -> Unlimited)
Batch'n'go - Expert Cactus Farmer (Max 100 -> Unlimited)

Both above challenges are now unlimited. :)
If anyone is against this change I welcome a new thread here in the suggestion section with further discussion towards the topic.