Such bargains exist because the manufacturers treat workers poorly and skimp on safety - many products contain toxic chemicals, may catch fire, contain sharp parts, etc. There’s also zero recourse should the product cause damage.
User "dal" offers a cheaper alternative (indirectly complaining that the Korg one is too expensive), while "blub" talks about that cheaper alternative is cutting corners.
So on talks about the Korg being too expensive, while the other talks about the aliexpress model being too cheap.