We need about 25 helium balloons for DD's party, and we will need the same amount again in a few months for DS. DD's party is on a Sunday so there aren't many places open to buy balloons. (I've been told I can get them the day before if I pay extra for hi-float but I'd rather not.) It seems easier and cheaper to just buy a helium tank and fill them ourselves. Is this as straightforward as it seems? Any tips for filling the balloons? Should I buy the optional "valves" or just tie them myself?
Thank you for any guidance!