Is Greater Link Spell as limitless as it appears?


I recently found this link, allegedly giving the text for two metamagic feats from Magic and Mayhem. The following, with typos corrected, got my attention:

Greater Link Spell [Metamagic]
You can cast any number of spells at the same time.
Prerequisite: Link Spell.
Benefit: As Link Spell, except that you may link any number of spells together.

Link Spell [Metamagic]
You can cast two spells at the same time.
Benefit: When preparing spells, you can link two spells together. These spells must then be cast at the same time; when you cast one, you automatically cast the other. The casting time is equal to the longest casting time listed between the two spells. (For example, if one spell has a casting time of "1 standard action" and the other has a casting time of "1 round," you need a full-round action to cast them both.) You choose all targets normally for the spells; they can have different targets or the same targets.
Each linked spell takes up a spell slot one level higher than normal.

Assuming that this is the correct text, is Greater Link Spell really as limitless as it appears? As I read it, I could have 100 fifth-level spells with a casting time of 1 round or less, prepare them all as a single Greater Link Spell with a casting time of 1 round, and this would take up one sixth-level spell slot with absolutely no other costs. Is this correct? I fear any Wizard that can cast Fireball 1000 times per round.