I have selected vendors just by using Amazon and searching for "Schizochytrium" and also for "vegan omega 3", and then studying the specifications and computing the prices per gram of DHA+EPA.
After eliminating all those with outrageous prices and those where the exact content of DHA and of EPA were not specified, for the remaining I have also checked the Web sites of the producers to see if they are credible, e.g. if they show detailed chemical analyses of their products made by independent laboratories.
I prefer to buy pure oil (in bottles) instead of capsules, and that is usually a little cheaper than capsules, while also having no useless excipients.
Even if someone does not like a faint sea food flavor, the oil containing omega-3 can be mixed with another cooking oil, e.g. with olive oil, and added to a salad or any other food that is not heated after the oil is added. In that case any flavor will be masked.
Examples of brands available in Europe (which have similar prices, of about half of the $1.63/g that you pay): SinoPlaSan, Norsan, Arctic Blue, Spoon of Change.
Your supplement appears to be the old kind of vegan omega-3, including only DHA and negligible EPA. Now there are better vegan supplements where EPA is about half of DHA, which is a good ratio.