Escaping it is the cheapest way to deal with it and won't affect what's stored in the database.
Replacing it with the ASCII code increases the storage amount (unlikely to be a significant issue) and will cause issues if you're pulling the data for purposes other than generating HTML. Note that the OP has never indicated that the details being input to the db will ever be pulled to be presented in HTML format. (Granted, he hasn't ever stated they wouldn't either.)
Right, if you try to do a replace with the VB character code, you'll end up with the exact same string value after the replace as before.
To deal with characters that would screw up HTML, you can replace them after you pull from the db. (Aren't there server.[whatever] functions to do this?) At any rate, what is best depends on one's needs and one's resources, though circumstances exist where there's not a significant difference in performance or convenience between the various alternatives.