A lot of folks remember the days when surplus 7.62x39 was at the "so cheap, they pay you to take it" level. Prices have gone up a fair amount even over the past couple years (by about $20/500 rounds). Availability is also more uneven, but it seems like the severe drought is pretty well past. Commodity prices, however, continue to rise (the prices of the raw materials like the copper and lead), so I do expect prices to keep going up. This is probably causing some to hoard it (better to buy today for $70-80/500 than in two weeks for $100/500), which could further restrict supply, but I haven't seen that.
If you can use some, buy some, but IMO, rumors of it becoming unobtanium are overblown.