Ask HN: Cost vs Performance for our BETA systems setup?

We are attempting to bootstrap our image processing service (http://www.pixtulate.com) and are getting ready to roll out our BETA. Naturally cash strapped, I am working out a minimum systems arch setup and trying to balance stability, performance and cost while keeping in perspective this is BETA. We are also trying to decide between hosting on DigitalOcean or Linode (like both a lot)

Based on testing, here is what we "think" our min requirements are to get started:

1. Load balancer with fail over (HAProxy or other) 2. 2 image processors (min 2GB RAM and 2 CPUs/each, but the more the better) 3. 3 couchbase nodes with 1 replica each (can get away with 256MB buckets since we don't store much here) 4. As much fast disk space as possible for image caching

With DigitalOcean, a bare bones setup will run about $70. Linode will be double ($140) but you also get at least double or more the resources (especially disk and CPU). Since this is BETA (and a small one at that), would you optimize for cost or solid user experience/availability? $140/month won't break the bank, but we would prefer to spend less.

With Linode we get decent headroom from day one while DigitalOcean scales cheaper.

Anyone willing to share their BETA experiences and what turned out to be important in their systems setup?