I hope this was a troll comment... Unless your thinking that the OP meant something other than the first 12 highlands.
Lowland Land 1 -Free Land 2 -1k Land 3 -3k Land 4 -5k Land 5 -30k Land 6 -150k Land 7 -300k Land 8 -750k Land 9 -1.5m Land 10 -2.5m Land 11 -3.5m Land 12 -5m Land 13 -10m Land 14 -20m Land 15 -60m Land 16 -100m Land 17 -200m Land 18 -300m Land 19 -600m Land 20 -900m Land 21 -1.3b Land 22 -1.5b Land 23 -1.8b Land 24 -2.1b Land 25 -3b Total cost: 11,803,737,000 (*11.8b) Highland Land 26 -3b Land 27 -3.5b Land 28 -4b Land 29 -4.5b Land 30 -9b Land 31 -11b Land 32 -13b Land 33 -15b Land 34 -17b Land 35 -20b Land 36 -25b Land 37 -30b Land 38 -40b Land 39 -70b Land 40 -80b Land 41 -90b Land 42-110b Land 43-115b Land 44 -120b Land 45 -140b Land 46 -160b Land 47 -170b Land 48 -220b Land 49 -250b Land 50 -300b Total cost: 2,010,000,000,000 (*2t) Hoarfrost Land 51 -5b Land 52 -6.25b Land 53 -7.8b Land 54 -10b Land 55 -12.5b Land 56 -15b Land 57 -20b Land 58 -25b Land 59 -30b Land 60 -37.5b Land 61 -45b Land 62 -60b Land 63 -75b Land 64 -90b Land 65 -125b Land 66 -145b Land 67 -185b Land 68 -220b Land 69 -275b Land 70 -350b Land 71 -450b Land 72 -550b Land 73 -675b Land 74 -850b Land 75 -1t Total cost: 5,254,050,000,000 (*5.25t)