I think the reverse question is how sovereign glue is "as powerful as some artifacts". It costs 2,400 gp - can you buy anything approaching the power of an artifact for 2,400 gp? That's per ounce, by the way (you normally find several ounces, but I'm not sure why given it costs another 1,000 gold worth of Salve of Slipperiness each time you use one ounce and want to retain the rest - spring for some more containers, cheapskate!).
If it required an L20 wizard to craft (if we were to limit crafting to your CL or below), that seems pretty cheap to engage the services of a 20th level wizard. Sticking things together doesn't really seem like an epic magical feat, especially compared to items at, say, CL 10. The fact that this is about as high as CL goes on items, and can be achieved by or before you can even access the craft feat, suggests CL isn't much of a limiting factor. It seems unlikely that would be overlooked by the designers - it's not like spellcraft was an obscure, rarely selected skill. If it were a limiting factor, maybe items should actually scale in power consistent with scaling in CL. All of that leads me to consider CL little more than flavour text.
In fact, it seems more reasonable to ditch CL entirely and just have the DC for crafting the item. Why bother with "add 5" at all? Then we could set DCs higher than 25, and consider how difficult each item should be to craft.
If it required an L20 wizard to craft (if we were to limit crafting to your CL or below), that seems pretty cheap to engage the services of a 20th level wizard. Sticking things together doesn't really seem like an epic magical feat, especially compared to items at, say, CL 10. The fact that this is about as high as CL goes on items, and can be achieved by or before you can even access the craft feat, suggests CL isn't much of a limiting factor. It seems unlikely that would be overlooked by the designers - it's not like spellcraft was an obscure, rarely selected skill. If it were a limiting factor, maybe items should actually scale in power consistent with scaling in CL. All of that leads me to consider CL little more than flavour text.
In fact, it seems more reasonable to ditch CL entirely and just have the DC for crafting the item. Why bother with "add 5" at all? Then we could set DCs higher than 25, and consider how difficult each item should be to craft.
