It's actually 48 minutes per stone. And some of those abyssites for reducing stone regeneration and extending time for stone are stupid easy to get.
You can even "rent" a whisker from the AH for one abyssite (you get it back so you can sell it back on the AH when done). Go kill normal Tonberries for another. Kill forced pop NM's for others. Think one or two may have been quested...forget exactly, there's so many of them.
As for not having the stones.... ummm.... why would they need a lot of them? If they came up the generally accepted way these days, they were leeching in a party that was giving them time extensions. Spend one stone to get in, leech a while and leave with 120 minutes to come back later. If you do it right, you can pick up time to add to your saved time and stay in there for hours without even spending a stone....which means you are steadily accruing them because you aren't spending them.
Jeesh... how many times is this concept gonna be discussed before it finally sinks in?
Feel like we're beating the proverbial dead horse.
For those that can't/won't/or otherwise don't use a wiki:
http://wiki.ffxiclopedia.org/wiki/Category:Abyssite
Clerity abyssites:
Traverser stones replenish 4 hours sooner. Existing stock is increased retroactively
Azure -- Defeat Tonberry Bedeviler/Cryptonberry/Occultist -- Abyssea - Konschtat
Crimson -- Complete quest Whither the Whisker -- Abyssea - Vunkerl
(buy and resell whisker from AH)
Ivory -- Purchased from Cruor Prospector for 9000 cruor --- Heroes of Abyssea
Sojourn Abyssites:
Enhances the potency of a traverser stone, allowing the bearer to abide in Abyssea for extended durations. Extends amount of Visitant time provided by Traverser Stones by 10% (+3 minutes per stone).
Ivory -- Purchased from Cruor Prospector for 6000 cruor -- Vision areas
Jade -- Defeat Mielikki -- Abyssea - Attohwa
Sapphire -- Complete quest Destiny Odyssey -- Abyssea - Misareaux
Scarlet -- Defeat Ovni -- Abyssea - La Theine
Emerald -- Defeat Waugyl -- Abyssea - Altepa
Indigo -- Defeat Assailer Chariot -- Abyssea - Grauberg
Then there are ones that increase how many stones you can carry at once, which are fairly simple to get as well.
Note also that some of those NM's can be SOLOED (at worst low-manned or a party of 6).