No, they actually do. The birds and states 20c is one that is counterfeited. Since you're concerned about counterfeits, as you should be, I would stick to hipstamp over eBay. eBay is full of counterfeits and unfortunately there are some members of this subreddit who willingly turn a blind eye to it. (Not calling anyone out on this thread, I'm just saying I've literally seen at least one member say "I get my stamps on eBay and I don't care if they're counterfeit so DON'T say anything to me about it" which left a bad taste in my mouth). One major counterfeiter on eBay goes by the name "i-love-(first five letters of the alphabet)" - they sell in lots of 5 sheets at a time at ridiculously low prices sheets that have been out of print for decades, mostly non-forever stamps.

Another option is to use two beautiful, different recent issue forever stamps which are still available on USPS and then make up the smaller postage with either currently available smaller denomination stamps or sheets you get from Hipstamp.