There is a limit of accepting 20 gifts per day. I have a suggestion, since you are required to have 25 neighbors to expand to 18x18 and 30 neighbors to expand to 19x19 (and more for the larger lots in FS). That you should be able to accept that many gifts per day as well. So if your city - farm is 19x19 you could accept 30 gifts per day. Kind of a bonus for expanding to the larger sizes since it is a requirement to expand and the cost to expand are large this would help recoup some (very small amount) of the cost. In farm story if you expand you can plant on all of the plots to recoup the cost but in city story the only way to recoup is for people to come and clean. The cost to expand to 17x17 is 700,000.00, that is an increase of 33 squares assuming you put something on each square that can be cleaned and that all squares were cleaned 5 times a day it would take 42 1/2 days to recoup the 700,000.00. The cost to expand to 18x18 is 850,000.00 and 19x19 is 900,000.