FTSE Global All Cap Index Fund (VAFTGAG) through iWeb

I've got a 12 month fixed cash ISA with Secure Trust Bank maturing in October and want to jump on the VAFTGAG bandwagon by transferring this all to VAFTGAG fund. I already have an account with iWeb; am I right in thinking iWeb simply charges you £5 per transaction and nothing else? While all other platforms are charging certain percentage commission/fee?

Since I'm transferring a large lump sum (22K), I think I'm best off with the single £5 transaction fee of iWeb? Or am I missing something obvious?