I'm going to second this and say that besides micro-transactions and apps, pricing at $1 is essentially signaling to the user that the product is near worthless. Its hard to imagine a product I would actively go out of the way to pay for that would cost $1 per month.
To me $1 per month signals that I should be looking for a free alternative or that it is an introductory rate that will increase later on. Gaming companies go out of their way to implement micro-transactions that are priced that low in another currency for a reason: it signals higher value to the user to spend "more". I'm not trying to give you a hard time, but this is a topic that has been covered time and time again on HN, and if you search you can find plenty of discussions around charging higher SaaS prices being more effective on almost all fronts.
Thanks for advise, agree with you about cost and sustainability of business.
If possibly could you tell then for what kind of service will you pay 10$/month?
I pay about that for hosting + email. But it goes to a big company and I've been using them since 2007 and the company is bigger now than it was then. To emphasize my point, there aren't many small companies that I would trust to bill my credit card on a recurring basis.
What will you do for me for $1/month?
Pricing at $1.00/month means that new customers + retained customers - non-collections = 200, $10.00/month means 20, $100.00/month means 2, and $2400/year means just one.
It's harder to acquire 200 customers than 20. It's harder to retain them. It's more work to process their payments and more costly due to per transaction fees. The channels that are used to reach such customers have to be lower cost and generally that equates with noisy -- think of app discovery for $1.00 apps in the appstores -- and $1.00 services are always directly competing with free.
I was going to say "web hosting/email", but then I realized that I wouldn't really trust a $1.00/month web hosting or email provider because at that price it doesn't suggest a sustainable business, and if it goes under after eighteen months, the pain isn't going to be worth the cost savings.
Pricing is signaling.
Good luck.