One could even argue costs per CHF are slightly lower if you invest less. Since if you open your account with a referral code you will never pay their ~0.5% management fee on the first 500 CHF invested. If you can do some referals yourself, that rises by max. 3 x 500 CHF to 2000 CHF.
The other costs scale linearly. Except for some things like getting out money for buying real estate (300 CHF I think). Look it up in their FAQ
Also, your own time spent on researching and managing this solution doesn’t get less if you invest less. But the big chunk of research has probably already happened and management is negligible.
On the other hand, the returns scale linearly and smoothly too, since you buy fractions of ETFs.
The question therefore boils down to:
- Would I invest any money with VIAC?
- Secondly, which of their strategies will I use?
That depends on:
- Your investment horizon
- Your marginal tax rate
- Alternatives to VIAC (doesn’t have to be 3a, e.g IBKR)
tl;dr: The influence of investment size is negligible or even in your favor.