There is 60 days stay visa that are multiple entry for 6 months. I think the original idea of "visa run"was to leave within 60 days and come back. Getting a new visa or enter again on except isn't the same
Now, i always like to consider that doing a Visa run, or extrention is as costly as just going to another country and stay there a month.
Not sure why people insists on staying put in one country all the time.... (If you're not working illegally, or trying to "live" there)
If you follow the rules and get passoort verification and address info from the embassy as your supposed to no need pay anything.
That some foreigners like to pay "money" to ignore rules and they say thailand is corrupt is funny. They themselves are corrupt for not following the rules ;-)
Find the rules and follow them and you shouldn't need to pay any extra. Especially if you got writing mwithon the rules.