Similar to how raider's boxes let you choose a raid item, or birthday tome boxes let you choose a tome, create a skill augment box that lets you choose any skill augment of your choice, not including UMD. Set the prices equal to stat augments of the same ML:
ML4 +3 Skill Diamond Box
Choose any one Diamond of Skill, except UMD.
59 TP
ML8 +5 Skill Diamond Box
Choose any one Diamond of Skill, except UMD.
75 TP
ML12 +7 Skill Diamond Box
Choose any one Diamond of Skill, except UMD.
95 TP
ML16 +9 Skill Diamond Box
Choose any one Diamond of Skill, except UMD.
150 TP
ML20 +11 Skill Diamond Box
Choose any one Diamond of Skill, except UMD.
175 TP
ML24 +13 Skill Diamond Box
Choose any one Diamond of Skill, except UMD.
195 TP
ML28 +15 Skill Diamond Box
Choose any one Diamond of Skill, except UMD.
195 TP
The problem this addresses: There are currently only three skill diamonds in the store for any level (Search, Disable Device, and Spellcraft) and those only appear in some of the possible MLs. And ALL of them, regardless of ML, cost the same as ML28 stat augments: 195 TP.
This suggestion would effectively put all skill diamonds in the store while actually reducing the store inventory. (Those three diamonds per level go away, replaced by one box per level.) Plus it would normalize the skill augment prices so that they'd be worth buying, at least more than right now in the store, where a +7 ML12 skill augment costs a whopping 195 TP.
The reason to spend dev time on this: It can (and probably would) generate actual sales.