Best way to get FC is through reward redemption.. Compared to Y redemption, First Class Redemption is sometimes 50% and sometimes double of a regular Y seat in terms of frequent flyer loyalty points.. so if you got some saved up over the years, this would be the way to go..

If you're paying, then the prices of FC is sometimes 3 or 4 times the price of a Y seat.. Maybe look at prices on www.hotwire.com or www.expedia.com and start comparing prices.. Once you have an idea what the prices are like, you'll know what a good deal looks like.. and post your results here and the FT gurus will get out their calculators.