Which party?

Short-term: No, this rate of increase is not sustainable. When both ETH and XMR hit their big bubbles last year, their price ended up settling at about half the "peak" value (and for ETH, triggered a major bull market, although they've yet to hit their highs again). For DASH, the question of course is "what will this peak value be?" If we stop here and reverse, then we should settle around .033 (just over $40). If we keep going up, then obviously that number would change. On the other hand, when BTC bubbled in late 2013, the bursting triggered a major bear market. So basically, nobody knows. (Wild guess? Between .08 and .1 as the peak, settling back into the .04 - .05 area long-term.)

Long-term: We have a budget system that creates a positive feedback loop. At the current prices, we have $500,000 per month to use to develop Dash, grow the ecosystem, fund integrations, etc. That's $6 million per year! Even if we reversed to .033 and stabilized around there, we still would have a $3 million annual budget. Bitcoin grew very slowly over the years as new companies had to be created to facilitate it (exchanges, merchant services, APIs). Now that all those things already exist for Bitcoin, and since Dash shares Bitcoin's code base, we can pay integration costs to those existing providers and bootstrap our growth. The potential is enormous. (Wild guess? About PayPal's marketcap, $50 billion, or approx. $5,000 per coin...assuming 10 million coins in existence when we hit this level.)