There seems to be a word missing there. Just about everybody has a 'disposable income', whether it be �5 per week or �5 million pounds per week. If your question is to make sense, 'disposable income' needs to be preceded by 'low', average' or 'high'.
Further, are there any restrictions on the type of goods you're allowed to consider. For example, could you include cars? (Rolls Royce, Alfa Romeo, BMW, Jaguar, etc). What about things like pens? (Cross, Montblanc, etc). Are you just thinking about fashion? (Gucci, Armani, etc). Or perhaps you want to concentrate on food and drink? (Taylor's of Harrogate, Dom Perignon, etc).
For a starting point (mainly fashion), look here:
http://en.wikipedia.org/wiki/Category:Luxury_b rands
Chris