Yes, I do consider Lamela good value. Spurs have been building for the longer-term, which means signing younger players. Lamela is still just 23 years old, has take time to adjust to a new league and new country, but has been pretty good for some while now - plenty of assists in the last season and a half, huge work rate and tenacity, and 7 goals in 18 appearances so far this season - which is why he's usually part of our starting XI.
Btw, 7 goals in 18 appearances this season is a better rate of return than that of Martial so far, who will potentially cost you more than double Lamela's price ... and Lamela isn't even a striker.