I went through a very similar process when building a product as an engineer (albeit B2B, but I think the same ideas apply here). When I first started, I wanted to undercut the market and charge what I felt was an extremely fair price (I was charging $8/month when competitors were charging $500/month). After scaling the product for a few years, it was eventually acquired, but one of the biggest regrets I've had is not charging more sooner, especially because the market could clearly support it.
Anyway, it's a bit unsolicited, but I could definitely see this being at least $4.99/month for Lite and $9.99/month for Pro. Congrats on the launch!
You aren't selling to techies. This is super easy to set up for almost any engineer (beyond a few fantastic features you added).
What you need to do is effectively twist the knife, make the reader feel the pain. "Don't you think $10 / mo is worth your sanity and a clean inbox?" essentially.
$10 is basically nothing to your modern professional. That's 1 - 2 coffee runs.
$1 or free (!!!) is way too cheap for an indie maker. Ignore the people who complain about price. There are always going to be people complaining, fire them. Those types will always find something to complain and twist your arm about.
Even $10 / mo for me, someone who has set this up myself, might be worth it just for additional features and being able to easily add more domains.
EDIT: Save free forever for the VC-backed companies who are burning other people's money in the hopes of hockey stick growth.
Free trials are fantastic, but free forever is a losing gambit in my opinion.
That makes sense. You (and your customers) definitely know the market, so data-backed decisions are best. Could also be an A/B opportunity for the future. Good luck, the product looks great!
You're right as it scales I may need to upgrade the server etc. but I think it will cover its expenses quite easily.