Buy quality and keep it for years. Life is too short to ride a bike that's 'just OK'.
The way I justify cost: Look at the utility cost, not the purchase cost. so if you're going to ride a custom $5,000 bike for 10 years, then you're utility cost is $500/year. Not really that expensive that way, and considering how health gains, fun, adventure & quality time we get from riding, it's an excellent value.