CurrentlyLog In are offering .com domains for $5.88 (plus ICANN fee) which includes one year of free WHOIS privacy. I don't know how long it will last and whether it will get cheaper with Black Friday or Cyber Monday, but it's a good deal if you are looking for a .com with privacy. They have other domains on offer too, and most come with free privacy too for the first year.
This is interesting. Is this a one time payment? I'm going to check if the offer is still available, it's been a while since you posted this though.
Namecheap do lots of offers, but that one has ended, sometimes they don't say when it will end. I would recommendLog In if you wanted a .com right now, as they are $8.99 with free privacy and you can use the coupon code GETMONEYOFF to get a $1 off, so it's $7.99 in total. I use them when I renew from other places like Namecheap when I have had an offer.
It looks like I'll be getting myself a .com domain quite soon. Unfortunately though most of the good domain names are already taken so even when there's a good deal like this one and I know I won't be getting the domain name I want sometimes there's little I can do except hope that when there are some offers at a later date, maybe I'll be lucky enough to grab the domain name I want if the owner hasn't renewed it.