Some of the more well stocked fish shops should sell normal brine shrimp eggs as well, eg Clementi Blk 328 the very famous fish shop.
.... I remember last time I was quite siao about them, probably spent $200+ on them over a few years of on/off enthusiasm, including mail order from Amazon even though my family was not rich, but used savings loh. They really captured my imagination back then, so I kept trying to maintain a persistent population of them, but they would always die early due to overfeeding probably, toppling onto the floor, or not last past the 2nd generation due to dunno what reason... But I dun regret it one bit, because now that I am adult, I dun get that sort of obsessive enthusiasm anymore, nor would I have the time and effort to splurge so much on them even though I have the money now, so I really treasure my childhood memories of joy from the enthusiasm I once had. 人生能有几次心动?能有多少我就要把握住多少。This video convinced me
https://www.youtube.com/watch?v=l_C8NdRrGoo