I've been thinking about that for a while, actually. Existing services are pulling in 6 figures of subscription fees monthly (e.g. Tactical Arbitrage, thousands of subscribers at $100/month). But I couldn't build something like that alone, would need to be a team and there's no way I could manage that kind of complex software and also run a reselling business.
I try to be the encouraging voice on HN, so here goes my pitch:
I think you could most definitely build it alone. Start with an MVP. Don't know enough code to build an MVP? Learn to code. Ruby or Python IMHO. Once you've got an MVP, dogfood part of your business through it. Iterate. Slowly, run more of your business through it. Once you're driving your entire business off of it, start selling it to others. You have the perfect testimonial: "We run our 300k/year business off of the platform, and its the core of our business".
You don't know what you can do until you try. Try.
