Great question. I have had a ton of clients/partners who are early stage startups encounter this exact problem. A pitch deck can be relevant not only for the round of funding you are targeting (which is usually its primary purpose) but even for things like business development and recruiting potential co-founders/mentors/board members/employees. Properly deployed, a pitch deck can be the Swiss Army knife of marketing documents for an entrepreneur.

At that price point and since your deck will likely be changing somewhat frequently given how early you are in the process, I would definitely find someone who specializes in build pitch decks specifically (versus your traditional design studio taking it on as a side project.) I would also recommend, to the extent possible, working with a company that can be available to support multiple iterations as you add/edit content over time.

I send most of my startup partners to a Chicago-based shop http://www.quick2launch.com/ for their initial pitch deck needs. I've seen them produce dozens of high-quality decks at a super affordable/responsive rate (not to mention they have some great online tools to manage your marketing materials moving forward.) Check them out - highly recommended for quality work production and savings.

Happy to hop on a call to discuss any other details/tips!