It'd be cheaper overall to buy Hylian and get lvl 29 techs.
Most attack techs are 8 DTs per tech, that's from donating to the server and redeeming via GM. Players typically run maybe 1 DTs cheaper (to 7 DTs per attack tech)
for 10 DTs, all 29 techs become level 30, and I personally would sell you lvl 29 techs for like 2 pds each