[mightybyte]

I don't think that it's wise to try to optimize for some kind of speculative long-term success at the expense of higher early-stage costs that reduce your odds of getting there. This is similar to companies that choose their initial technology with scalability in mind before they're even remotely close to needing to scale. I've actually done this only to discover that scalability has a very definite cost and when you're small it has an outsized impact on your burn rate. If you have success, you're going to figure out a way to make the changes you need. Case in point: Facebook. They successfully grew a PHP codebase into one of the most popular apps in the world. It definitely cost a lot more money for them to make PHP work, but when they got to that point they were a lot less cost-sensitive.

Planning for that far down the road is the least of your worries. And any plans you make along those lines are not likely to be very accurate anyway. You're much better off optimizing for the near to mid term. Based on the hosting costs described by the OP they are already reaping a tangible value here.