20+ years of experience with spreadsheets and 10+ years as a full stack web developer recommend me as the best freelancer for this job.
Although my hourly rate is a bit over your hourly budget, I know my trade and I deliver the best quality in a short amount of work time. While you might get a cheaper project even from the beginning, the gains will certainly be visible on the long term.
Without knowing the specific details of your business, here is the general approach I take for such a quoting template:
1. Break down the specific tasks and their unit of measure => results a general sheet, to be used for all the projects;
2. Define the modifying rules (eg. the price for urgent tasks / projects would be increased by x%)
3. Define the presentation template => intuitive, easy to use, based on the structured data already defined, and visually appealing, using the brand identifiers (logo, letterhead, fonts, colors, etc)
4. Test the tool on actual data
Let's have a meeting at your earliest convenience and go over the details, then we can make the implementation plan.