Great work.
A better system would be to allow bids. Bids should open at base price for example in this case 12$ for a plot. if the number of bids exceed no. of plots people will need to bid higher than 12$. This will be fair for everyone. and there won't be any luck/lottery around.
for 30k plots, bids can be divided into 3 types may be 10 regions, 100 tracts and 10k plots or whatever combination you feel is the best. Do consider bids in next presale.