Server change 32slot to 64/128 slot

Hi;
If I have an account (Element Club Argentum/Aurum/Platinum) and want to have only 1 slot or 1 slot on my server, do I have to pay per month or do I have to purchase an account once?

Do I need to purchase a monthly account? (Argentum/Aurum/Platinum)

I know I have to buy my monthly account here:

But I want to know what’s the difference between the three accounts?( (Argentum/Aurum/Platinum))
Do they have a 1/2/5 limit?
Do we have to pay again every month?
Just to increase the number of people and slides!

have you read the description(s) for Each ?

Looks to be like some feature(s) like user slot capabilities and bg and text color(s) some other benefits