But of course the OP knows better than the people
who quoted.

Was that meant to sound bitchy? I don't know anything about it, I
just don't have the money to pay for scaffolding.

Not really, but your original post sounded as though you felt scaffolding
was unnecessary even though the company quoting did. It is not unusual to
find people have a quite unrealistic view of what may be required. If the
company is professional then they presumably feel the job requires
scaffolding to do the job safely. By all means get other quotes but don't be
too surprised if they say the same.