'Natural pearls' sounds great... perhaps they are (I am no expert to say 'yes' or 'no', but can't see any reason why they wouldn't be, from the details you have posted, Bodecia). As for price, frankly, I would expect more than $100 but well less than $1000. Sure enough, I'd be happy with the lower end of the range, esp. given the irregular shape of the pearls. It may be a while until you find another, but ...
Can't say I have the perfect price or quality reference either. I am used to see graduated strands from about 2mm to about 6mm. And their higher quotes includes fancy clasps sometimes.
Are you planning to wear them a bunch? b

I love small - even seed size - pearls worn with enhancers

, but it is not the most common 'look' folks expect from pearls.
Looking forward to see the roundish 'naturals'. The small ones can be quite round without causing a stir.