From my experience, higher priced items typically sell slightly less, but it evens out in the long run since you’re making slightly more. The monthly average (sales/income) in the portfolio section helps when deciding whether or not requesting a price change makes sense. If your item is really new, give it a chance to make some sales before comparing numbers – focusing on a long-term earning strategy. Also, you may want to take other things into account such as support – since selling fewer items at a higher price also means providing less support. Since the item is part of a series, there are also ways to use your other series items as “entry-level” purchases to promote and boost sales for your more expensive item. I’m sure you’ll get plenty of great advice
Best of luck!