Descriptions from lowest:
The basic structure is forming up.
It slightly resembles a chest.
It is missing a lid.
It is still quite shaky. (6 logs)
It looks like a small chest but it could be so much more. (1 slot, 9 logs)
It does not look quite safe yet. (12 logs)
The base looks strong now but lid is still quite weak. (2 slot, 15 logs)
The chest is looking much larger. (3 slots, 21 logs, small skeleton)
The construction looks bigger and bigger. (27 logs, 3-4 slots)
The structure is now stronger than ever before. (35 logs)
The chest looks big enough to hold out several equipments. (44 logs)
The extra material has made the chest almost impossible to breach.
The chest construction looks quite large and safe. (7 slotter)
The extra material in support-structure quarantees quality.
The chest looks just perfect and there is very little unfinished.
The construction looks very big and sturdy. 

Reinforcement (quality is better than quantity):
The reinforcement looks totally incomplete.
The reinforcement is still quite weak.
The structure looks much stronger because of the reinforcement.
The reinforcement still lacks quality.
The reinforcement looks fine but it could be improved.
The reinforced chest looks quite sturdy now.
It would be a pain to force through the reinforcements.
Just a final touch and the reinforcement is fully complete.

Locks (best materials - diamond, dukonium):
(ok: titanium, zhentorium, iridium, good gems, oak)
(Bad: tadmium, mowglite, tin)
The lock looks totally incomplete.
It slightly resembles a chest lock but much needs to be done.
The basic structure is forming up quite nicely.
The inner structure looks almost completed.
The lock still lacks all the rolls.
The lock looks somewhat ready.
It looks like a primary lock but it could be so much more. (1 dial, 10 combo)
The extra material in mechanism should pay off.
The lock looks very complicated.
It looks very strong, almost impossible to break. (1 dial, 15 combo)
The mechanism is now stronger than before.  
The quality of lock is very high but dials could be more sturdy.
The lock looks extremely strong and supreme quality.
The lock looks incredible strong and divine quality.

Traps:
The trap is forming up.
The outer structure looks strong enough.
The mechanish looks somewhat trimmed.
The structure is now sturdy but small in size.
The triggering device looks sophisticated.
It looks like a basic trap but it could be so much more.
It is a clever and nasty looking trap.
The trap is complex and more protected against disarming.
It looks very small yet lethal machine.
It is an awesome trap but it could be superb.
It is a superb trap by your standards.

Skill limits what material one can use for chest reinforcement:
70% or so: iron, aluminium, tin, ebony...
79%: silver
Over 80%: mithril, durandium, steel...

Pricing guide (locks add value):

1 slot: 18-30k (tiny wood box)
2 slot: 30-45k (small wood box)
3 slot: 50-80k (wood crate)
4 slot: 80-110k (large wood crate)
5 slot: 120-150k (classical wood chest)
6 slot: 160-190k (wood chest)
7 slot: 200-250k (small wood sailor chest)
8 slot: 250-325k (big wood sailor chest)
9 slot: 330-375k (Diamond Safe)
10 slot: 380-450k (Massive Diamond Safe)
11 slot: 450-525k (Large Diamond Vault)
12 slot: 550k+ (Gargantuan Diamond Vault)