Sure, it could cause you problems. For my my highest pricing tier (although I don’t have tiers per se) is $500 / month. I probably wouldn’t take on a $2k / month customers b/c I probably wouldn’t want to deal with structure and headaches of that sized business.
But it won’t necessarily cause you problems. And 24/7 support isn’t a must. The word “enterprise” is kind of a buzzword to start with, and it doesn’t require any specific level of support.
I just checked out both recurly and keen and neither of them mention 24/7 support in their “enterprise” plans. In fact, keen’s support sections says they’ll reply back to support ticket within 24 hours.
I’m not sure what line of work OP is in. It certainly may be the case that for his industry, 24/7 is a must. These are just two reasonably established saas apps that happened to pop to mind for me.
And while we’re on the topic of 24/7 support, not all 24/7 supports are created equal. In some cases, you get tier 1 support that’s basically meaningless, whereas in other cases you can get access to high level techs/employees 24/7. Two completely different balls of wax.
I didn’t mean to suggest that you should treat the enterprise plan as something trivial. Obviously these would be your highest value customers and you would want to take care of them and give them value corresponding to what they’re paying.
But I think a good starting point is to simply throw up an Enterprise tier with a few simple differentiations, and take it from there.
At the end of the day, even if all you are doing is charging them more (with literally zero additional features or support), they still may prefer to be on a higher price tier. Because for one, it’s not that much money for them anyways. And for two, you’re always going to pay more attention to issues from higher paying customers.
Businesses of a certain size don’t want to be on a $20 / month plan, because they understand they’re going to get treated like a $20 customer. They want to be treated like a $200 or $2k customer.