Just because Samsung could earn a higher profit using their own chips, doesn't mean that Qualcomm should license it at that price. They could in theory compete on quality, or power at a higher price tier. Nothing in FRAND indicates that you should let competitors maximize their profits.
Second, this isn't about earning higher profit. but whether Qualcomm is abusing the standard essential patents to prevent competition and maintain their dominance. Qualcomm doesn't want to compete with anyone on quality or price. ETSI which governs the wireless standard forbids such anti-competitive licensing practices outlawed by local powers.
Sure, SEP/FRAND isn't about promoting competition or best price, etc, but it is certainly about interoperability and everyone having fair and reasonable access to the underlying IP's to achieve the ideal.
Given how vague it is, I think the way to determine what's fair is to look at the effect on the market. I think their socket share is 60-70% which is the lions share, but not at the point to be considered a monopoly. They can't double thier rates without loosing market share.
In my view Qualcomms market share is largely due to how efficiently they have integrated all the wireless technologies into one package. If intel had a single efficient multi band package for LTE/3G/2g/wifi/bt etc... the extra 2% licensing costs would be offset by the battery savings.