Honestly I think you are giving away too much on the free plan. You should try removing the free plan and have pricing like: Hobby => $8 Business => $29 Enterprise => Contact Also, where are you located, since I noticed that you spell organization as organisation. :-)
Honestly, I'd scrap everything up to $29/mth and change the pricing basis from MB and number of queries (people who use spreadsheets have no real understanding of this) to number of spreadsheets. I remember working for Deutsche Bank 15yrs ago when one Excel spreadsheet could make them millions of £/day — don't be afraid to charge a decent amount! People who care about data, have spreadsheets, and need some interopera…
N.B. I'm not bashing sheetlabs, just saying that sometimes the most important part is not the numbers in the cell but how you create them