If you want to be a greenie your in the wrong place you need to come to PDX  were your breathren are.. that's all these folks talk about and protest about...

Though I paid $305K, is there a chance I can successfully protest the 50%+ increase? 

The biggest thing is the eviction moratorium, especially on landlords with lots of lower rent places that are seeing like 80% (or less) collections.If protests are the only thing, then that's nothing.Once the lockdown and moratorium goes away, I think we'll return since lending rates are low. 

I had initially planned to protest on my own but I am looking into professional consultants as it may be worth the cost to save myself the headache...

In fact, sites like Facebook, Twitter, BiggerPockets, LinkedIn and so on would not be able to survive.Here's a brief post with some links to information about SOPA I put up a short while ago: BiggerPockets Offline This AM: Protest SOPA

Keep in mind, you will not be able to protest until next year as the deadline is May 15th an/or 30 days after notices are sentCollect information to defend the value of the property. 

I used fivestone tax advisors last year but they failed at winning the protest.

If you have neighbors that don't want it, be very wary I have seen many a well thought out plans and developments fall at the city or county due to protest of the neighbors.

We had something like a 30-day cancellation policy originally, and I protested this change.

To confirm, ($1448.244 - 1379.28)/1379.28 = .05 = 5%.Using this example, it seems worthwhile to protest my fair market value only if I can get it to be less than $105,000.