well, there's a way to counter this, get the developer to provide you with website management software,
some developers use professional softwares to build websites where "clients" get to make minor updates and such thru a windows-based user-friendly software, get your developer to build your website this way
or, pay a retaining fee every month so the developer would be on standby to cater to your needs at all times, this would be a better option if you foresee a lot of changes all the time
