Don't understand "Buy for Group"

I made a group, and attempted to buy land for the group, but it said I have "insuffient land maintenance credits."

What does that mean?

I'm making a group of myself and 2 alts. I want the land so the alts can use it for whatever they do, without having them use the land I already own (though maybe I should just allocate some of the land I have to them...how would I do that?)

Why must this be so confusing?

it means ... goto group .... land, and assign your tier to that group ... essnetially you have to donate for the group to use, it doesnt sort of KNOW about your tier untill you donate it ...even if you own the group ... also note ... you MUST have more than one person in a group or it will disband

Thanks, that seemed to do it.

Plus it kept me from going over tier.