* I doubt offers will be as plentiful as Show, Tell, Ask.
* Offers also expire where Show, Tell and Ask are relevant for a longer periods of time. Mixing Asks, Tells, Shows, and Offers + others together allow irrelevant or aging submissions to slide, making a more useful "offers page". It makes offers compete in some sort of page ranking, instead of a usually unchanging page.
* If I want to see a recent, hot Offer, I'll see it on the top page. If I want to see medium-aged offers, by mixing them in with asks, I'll see other interesting content as well. It is a more useful offers page. Making a separate offers page will have me polling a page that doesn't change usually.
* If I want to see very old offers, I'll use searchyc, google, or check jacques' blog. Chances are I won't be doing this that often because very old offers will be expired.
edit: totally implemented, probably before I posted even a long time ago
In that case, with an offers list on the next invocation and a very functional asks link, I don't think an extra link on the bar is necessary
Submitter, your link in your profile appears to be broken. I attended school with someone sharing your name (doubtful it's actually you) and was going to look up your profile. Just a heads up.
Might go along well with http://news.ycombinator.com/offers