Nice rig, this is my setup used for the EverGreenCoin:
Solar panel- ( US $7.46 / piece)3 pcs- total price: 22.38 USD
http://www.aliexpress.com/store/product/6V-4-5W-720mA-Mini-monocrystalline-polycrystalline-solar-cell-battery-Panel-charge-for-small-solar-power/319525_1798866398.html?spm=2114.10010108.100007.59.cyZxt3
Solar MPPT charger- 1 Piece $9.37
www.aliexpress.com/item/30A-12V-24V-Auto-Switch-MPPT-Solar-Panel-Battery-Regulator-Charge-Controller/32292330005.html?spm=2114.01020208.3.19.0givqS&ws_ab_test=searchweb201556_1,searchweb201644_2_10001_10002_10005_10006_10003_10004_62,searchweb201560_8,searchweb1451318400_6148
Total: $54.44