My advice will likely be different than most. If money is important (meaning you’d really rather not spend several thousand dollars more), go with the KS7s. Do not try out the OPN1 because there’s a good chance you’ll like them better. You’ll learn a lot in the first few months of having the KS7s and likely have the opportunity (if you wish) to upgrade to KS8s that will likely be coming out sometime in Spring. If, after trying out KS7s (or possibly KS8s), one can always go buy OPN1s (or whatever is latest and greatest at the time) On the other hand, if money isn’t really an issue and you like having top notch tech, go with the OPN1s. If you go online, I would expect to pay around $4000 for a pair, perhaps a little less. $2000 was likely for one hearing aid.
For a first time user, I’d highly encourage an in person fitting. You’re likely to have a lot of questions.