Gfinity - Minimum 3000 buy

Why do you have to buy 3000 shares minimum? I’ve bought micro caps in the past and never come across this. I know EMS applies to selling but does this also apply to buying on some of the smaller stocks?

I was thinking the same. I have Gfin elsewhere but would be great to add more under my Isa wrapper. 3000 per hit though puts it out of that arc.