Are you referring to the Gallery Plus?  You mean you want to buy the monthly service for one  month so you can upload up to 3 images per day during that month?  You can but the set up fee is $5.00 (I think that is correct) then you have to pay the first month of service (which is $5.00 as well I believe). You would have to remember to cancel the service before the month timeframe is up so it won't charge you after the initial set up fee and first month fee.

Hope this helps, if you have additional questions regarding this please email store@renderosity.com for assistance.

Thanks