Search the exact domain before broadening the comparison
First decide whether you need a previous sale of the exact domain or completed sales of similar domains. Search the full name including its extension in a reported-sales source, then check the original public report or venue record where available. A similar name is a comparable candidate, not the transaction history of your domain.
If the exact-domain search produces no useful record, broaden one dimension at a time: the same extension, similar word structure, then the same commercial meaning. Keep those groups separate. A short dictionary word, a two-word service name, and an invented brand should not share a price benchmark solely because they contain the same letters.