simple vhdl question

It depends on where you want to do it. If "000" is the value of some signal - say some_signal and you have various options then use a case statement, e.g.:

case some_signal
    when "000" =>
        PRICE <= "110010";
    when "111" =>
        PRICE <= some other value;
    when others =>
        PRICE <= some default value;
end case;

note that the case statement has to be within a process. You could do if then else:

if some_signal = "000" then
    PRICE <= "110010";
else
    PRICE <= some value;
end if;

If you don't want / have a process then you coule write it as a concurrent statement - i.e just on its own:

PRICE <= "110010" when some_signal = "000" else "some default value";