I use their "Advanced" billing mode which is usage-based and ended up cheaper than the fixed-price "Simple" mode. This was my bill for last month (received ~300 emails):

    Total: $0.35
    Storage (GB/month): 0.00 ($0.00)
    Emails sent to non-Purelymail accounts: 19 ($0.00)
    Emails sent: 19 ($0.00)
    Emails sent (GB): 0.00 ($0.00)
    Yearly account fee (days): 30 ($0.33)
    Shared-domain user fees: $0.02

They don't actually support wildcards, but there's a matching pattern "Any address starting with" for which I just entered "evidlo".

https://purelymail.com/docs/routing