qaulity comes first, cheap filler is generaly like iron to sand down, doesnt flex well so can crack, and doesnt always adhease to the metal well, i usually use U-POL EASYSAND, and U-POL TOPSTOP to finish, used both for about 12yrs and never a problem, its a bit like the spay filler , i always use U-POL REFACE, cracking stuff, doesnt shrink when set and very easy to use, i've used more expensive and cheaper products but always found the best results with these products, paint is a different thing alltogether, different painters have there own preferences, my friend owns a major bodyshop in wrexham, he hates dupont i love it, he likes ici i dont, but we both agree that ppg used to be the best BLOODY EXPENSIVE BUT THE BEST!!! unfortunatly unipart have stopped selling paint my dads augusta and my appia are both painted in PPG DELTRON but my augusta fulvia and integrale are painted in dupont