Thanks, but I'm not seeing the answer to my question. In fact, the first link says that luck doesn't affect treasure chests. I was wondering how to determine the effect 1000 luck had on a treasure chest.
Read both links. The first explains how to calculate the effect of Luck, and also has calculators for you to use.
The second link, explains that as part of Pub 86, and the Global Loot Revamp, Luck does now affect treasure chests
Additionally, if it is a Felucca map, there will be an additional 1000 point Luck bonus applied.
Your first question, "Is there a way to estimate the effectiveness of luck?" is answered very well, in fact, that you can calculate the effect instead of estimating. You can even say ok if I want %50 chance at improved loot, I need X Luck. And you can calculate that X.
Your second question. "I doubt ill be able to manage more than 500 luck, and just wondering if it's worth trying to build such a suit." That is subjective and totally up to you.
You CAN find the exact %effect of 500 luck. I would like to point out that, 6*140 = 840 is pretty easy to fit into an LRC suit of leather. But back to your question of the 500, assuming that is all you can fit
due to reasons, 500 luck gives you a 31.581% Chance at *more loot, more properties on loot, and chance that the properties will be higher than normal intensities. All right off the top of the Luck link at Uoguide. You may notice the asterisk I put on more loot. Someone else will need to chime in, on whether or not Luck can boost number of items in a chest. Typically there is a set number for each level 1 - 7 of a map.
Hope that helps. Don't forget the luck statue! There is at least one publically accessible and Luna, and it is not uncommon for folks to put them on steps or a porch for people to click. Since we have confirmation that Luck bonus is applied when you dig up the chest
(there is a nice link with answers from Kyronix you may have missed in DreadLord Lestat's post), once you have a couple of decoded maps, and you've found your spots, click a statue and get a little extra luck. The luck bonus is 200 plus 50 for for each year of continuous subscription; the maximum is currently 1000 and the minimum is 200. You can use it once every 24 hrs. The way it works with treasure chest is even better. Say you only have 45 seconds left on the bonus and you dig up your last chest, no problem! The bonus has been applied

But say you were idk, fighting a Paragon NastyThing and it took you 46 secs to make a corpse, byebye luck bonus.
Don't forget the Etoile Blue / Novo Bleue caster luck jewelry set, there is 400, usually 4 or 5 mil, and the 95 luck robes are cheap. look for Robe of the Eclipse on vendor search. You can do 1135 @ 6x140 + 2x100 imbued jewels + 95 luck robe. add 200 to that number if you pick up the Bleue set. Theres more, but thats just 2 quick ideas. Good Luck with your hunting