I very much like the idea of a something to spur people on to find chests - why not have more potions you cannot get anywhere else, or even a few potions with a difference such as:
- muscle enhancer (adds +2 to your damage stat permanently);
- kendal mint cake (provides some stam immediately as if you have just earned a stam regain);
- bulging pockets (adds +1 bp space permanently);
- the taxman cometh (doubles guild tax for 24 hours for all guild members);
- guild bonanza (casts a buff on all guild members for 24 hours of their choice).
And can we have different ways to open them - perhaps they need an item to open them rather than pay LPs or gold for a key. Perhaps a resource drop that has to be obtained - the greater the difficulty the better the reward.
Just some random thoughts