I used to work for a large F100 company where I had to know no later than June 30th what my expected expenses would be for the next fiscal year (January-December). Any increase in expenses or acquisition of a new product required going through an extraordinary escalation process. Smaller companies may be more flexible but also may not be able to absorb price increases.

For what it’s worth, the same F100 company was notorious for taking anywhere from 90 to 180 days to pay invoices…because it could. If your price is above a couple hundred (US) per month you may not be able to just use credit cards/paypal/etc and need to learn the ins and outs of procurement systems.