Google throws up quite a lot of it, eg:
When you hear about the benefits of federal consolidation, you may think that it is too good of a deal to be valid. Lower monthly payments, fixed interest rates, and additional benefits are offered--all without a credit check, income verification, or fees! It seems too good to be true, but this is one time when you can believe the hype. http://www.lawschoolloans.com/articl...x.php?id=20019
However, I feel this is not good grammar. Could you analyse it?
You are right, it is poor grammar, but it has unfortunately become more common in usage. The proper expression used to be "too good to be true." The author of the phrase could have been used in your original example without changing the meaning: When you hear about the benefits of federal consolidation, you may think that it is too good to be true.
The rule of thumb is that if something sounds too good to be true, then it is usually a scam or a bad deal of some sort.
Google throws up quite a lot of it, eg:
When you hear about the benefits of federal consolidation, you may think that it is too good of a deal to be valid. Lower monthly payments, fixed interest rates, and additional benefits are offered--all without a credit check, income verification, or fees! It seems too good to be true, but this is one time when you can believe the hype. Federal Loan Consolidation, Lower Monthly Payments, Fixed Interest Rates & Longer Loan Term
However, I feel this is not good grammar. Could you analyse it?
I had never heard or seen this structure with the “of” after the adjective. You say Google throws up quite a lot of it so I checked it out too and was amazed by the frequency. The same goes for other adjectives: I checked out “too tall of a …” and it was the same!
I can’t find it in any grammar books. For example, if you take a look at Thomson and Martinet, “A Practical English Grammar” (Fourth Edition, 252A2, p.224) you’ll find this:
too + adjective + a + noun + infinitive He was too shrewd a businessman to accept the first offer…. He is too experienced a conductor to mind what the critics say… .
No mention of an “of” after the adjective.
Maybe this “alternative” structure will end up one day by being considered as acceptable and even replace the structure exemplified in the Thomson and Martinet (like “me” for “I” after the verb to be ; or “who” instead of “whom”).
I have just checked out on Google the comparative frequency of the two structures and the accepted one is still winning the race:
Too good a… 285 000 occurrences Too good of a … 219 000 occurrences
Too tall a … 6290 occurrences Too tall of a … 4990
too good of a 
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