I found a great price on Meostars non hd 10x42, new and within $100 of Primes. For those who have Primes, how do they compare. What would be your choice?
Good question and frankly there may not be a good answer as I doubt anybody has much experience with both. I have some experience with both of them. so I'll give this a shot. Please keep in mind my comments on the Meopta are from memory and notes I took about them, so this may be a little shaky

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When I first started out looking for a serious upgrade to my Nikon Monarch ATB, the Meopta Meostar was one of the first things I became curious about. However, it took quite some time before I actually found one to look at. Those who have the Meostar can comment on this, but here are my impressions. It is a great glass. It has some things I really did not like. On those I have seen, they had a decided yellow color bias. This bias is there and really does not affect the image, but personally I prefer a reddish bias to a color neutral bias for my use. This is on the 42mm Meostar, the 8x32 has a more neutral image tint. Not that anybody won't get used to the slight yellow of the Meopta. Next I am not real fond of the way the diopter adjustment knob protrudes from the center focus knob. That looked to me like the cause of constant diopter adjustment problems. However, Meopta has kept the feature and evidently did not have cause to modify the diopter to alleviate any service or warranty issues. Lastly the Meostar has a sort of "nose heavy" feel for my tastes. These are nit picks, there is not a lot to dislike about the Meopta Meostar.
The Prime is really too new to really have been shaken out properly. I'm still looking forward to seeing the production runs of the 8x and 10x that are hopefully headed my way on Monday

. Taking the image from my 10x beta review model and using my memory (never a completely reliable reference) I'd say the Prime is brighter, has a little better edge performance, and I do think the image is a little flatter. There is not enough center field resolution differences to be notable, as I remember the Meostar. The thing that remains to be seen with the Prime, as I see the issue anyway, is the reactions of people to the large diameter of the Prime HD eye cups. I wondered about that in the review I did. I also wonder since I said something about it if people are not looking for some issues. There have been lots of posts initially remarking about blackouts and then re posts from the same users saying they really are not an issue. I can't get blackouts on the beta sample I have, my issue is they take some simple getting used to because they make the binocular feel different when you are holding them up to your eyes. That issue is now a non issue (to me anyway). There is also evidently an eye relief issue with the Prime, likely much more of a problem for eye glass wearers. I am not needing glasses with binoculars, so frankly, that does not present itself as an issue to me, maybe to you if you wear glasses.
Both are built pretty stout, I doubt a normal user will be able to break one. I happen to prefer the right eye diopter of the Prime as well as the focus wheel of the Prime. I have little doubt the eye cup of the Meostar will fit people who have a narrow IPD, small diameter eyes, or who have eyes set in relatively deep sockets. So if your facial features resemble that, then frankly the Prime will have to either pass/fail the up to your face comfort test.
Optics on both are good enough to last for a good long while and have the build quality to get the life out of the view. Hope this helps some. B
Edit to add: Maybe Frank will chime in here. I seem to remember he may have more eye time with the Meostar than I do, and he also had the Prime.