Tell the customers with the small gates you need to have a small gate surcharge.
You need to have a pricing structure where is you charge $30 for a .25 acre/11,000 sf. You can not be charging $30 for a .5 acre/22,000 sf.
You need to not only have prices for .25, .5, and .75 acre but for every 1,000 sf between those units.
Say a 1/4 - 11,000 sf, and .5 acre - 22,000 sf, has a price difference of $10. So a 16,000 sf property should be charged $35.