if you want my opinion your not gonna find something good under 70$
for a good keyboard you can look on banggood theys propose really good keayboard or you can check at Epomaker website the most cheap and good mechanical keyboard are generaly the 60% keyboard
Redragon, Tecware, GK61/RK61. Not sure about pricing in your country, but those are pretty cheap and are decent quality. If your budget was a little higher Epomaker is a good brand.