Here is the build buy mode enabler for all expansions up to BV by request. I have also posted it here at my site:

http://simswithcomplements.googlepages.com/mods.html

If you download it from there, you will find it directly below the seasons enabler on that same page.

Test it out for me if you have all expansions up to BV and remove it immediately without saving if there is a problem. With this hack, the disable mode should never appear again - after all it's your game to do as you please

Cheers guys,
Mark.