There are different opinions as to whether one should buy a lottery. The following is from R’ Yitzchok Landau, the assistant of the Ruv Z”L for many years.
“Once, a Chossid bought a lottery and asked me to ask for a Beracha from the Ruv Z”L that he should have Hatzlacha in the Gorel (lottery). I did so and the Ruv Z”L gave a Beracha. Then the Ruv Z”L asked me, “Do you also buy the lottery (a “luz” in Yiddish)?” I responded, “Once in a while”. The Ruv Z”L said, “Very good.”
On a different occasion the Ruv Z”L recounted, “Itche’le Karniel (a Belzer Chossid from Lvov) suddenly started sending barrels of gold to Belz. People said he won a lottery”.