It depends what you call expensive, I use Toni & Guy, which are about �5 each for shampoo and conditioner or if you are going to Boots they are doing a 3 for 2 deal on them.
I would have to suggest that your question is impossible to answer. What works well for one person may not be the most pleasing for another. As cost is obviously important to you then I suggest you do what I do and try supermarket own brands until you find one that you are happy with. They are about the only grooming products that are not grossly overpriced. Most products are just big profit generators because the manufacturers are playing on our vanity and know that we (or most people) will buy because of the image etc. Just like trainers - big name brands are all way overpriced; lesser known brands are cheaper and often better made ......... but, fashion dictates.
vo5 - I am allergic to loads of shampoo and this is one of the rare shampoos and conditioners I can use with out problems. I have waist length coloured hair that gets very tangled and it can even cope with this and all for a little under �2 a bottle.
I have the same problem! The best I have found is Pantene brand. I use the shampoo for coloured hair, and then the 'daily moisture renewal' conditioner. That has worked really well. Herbal Essences didn't quite work for me, but, who knows, it might work for you. This will be an experiment for you!
Aveda Sap Moss shampoo and conditioner. Quite expensive to buy but very economical to use and saved my life when highlights went wrong and left me with white straw textured streaks