Funny thing. Two weeks ago I tried (and succeeded) to setup a discourse forum for some old friendsā¦ and faced the exact same issues.
Digital Ocean didnāt allowed me to chose the lower plans as it was greyed out. Accepted it and went with the 12$ plan, although this was quiet a bit over budget for a little āplaygroundā.
Then setup everything with Mailgun. Added credit card and was automatically switched to foundation trial - which will lead to 35$ afterwards, although I will probably just send 100mails per month.
I found information about their flex plan and the pay-as-you-go but no option to change it myself. Had to contact the service and they now changed it to flex plan for me.
So, there are a few things which didnāt went as expected - overall leaving to the impression that you will be charged more if youāre not paying enough with your attention.
Somewhat obvious, but the instructions and information I gathered before through various tutorial showed a different picture (totally easy and cheap, just use the smallest plan, free option, etc.).