I've never regretted buying a bag because I stop caring about how much I paid for a bag after I've bought it and it's no longer possible for me to return it. This means that instead of thinking 'I spent $xxx on buying this bag', I think 'I own this bag'. There is no decision-making involved in acquiring the bag and hence nothing to regret.
Sorry if this doesn't make sense. Heh.
Sorry if this doesn't make sense. Heh.