Crypto mining hardware vendors in China are delighted these days seeing the price of their secondhand mining machines doubled as a result of the recent bitcoin rally.

In the eye of Zhang Xilin, a mining equipment vendor in Huaqiang North – China’s No.1 electronics street and world’s largest distribution center of mining rigs, this April is their golden month in the past six months. “The price of second-hand mining rigs have doubled,” he said excitedly, and began to recommend the Antminer Z11 which he claimed one of the most popular mining hardware these days.

The bull run starting this April has driven bitcoin back above $5,000 after 4 month-long sluggish. It has led to a massive rally in the crypto market, among which Zcash surged 33% in the same week. These businesspeople have already sensed the market change and been well-prepared.

In March, Antminer Z11 is rolled out priced at $1,242 on Bitmain’s official website; seeing the stock decrease quickly, the company bid up the price higher to $1,515. Zhang said he was one of the few who have successfully purchased Z11 and decided to resell it at 13,000 yuan ($1,911). Though priced one-third higher of the initial price, his 50 units of Z11 were snapped up soon. Along with the Z11, Zhang also sold over 100 units of S9 at satisfying prices.

“First the price of M3 surged, and then T9 and S9,” Kennen, a mine owner, said his wechat is recently bombed with messages asking about crypto mining. After bitcoin stood back above $5,000, Kennen said he saw many orders from bosses in various industries inquiring for thousands of mining machines.

Last December after bitcoin crashed, bitcoin mining rigs were reportedly sold by the kilo and even dumped like scrap. While Kennen said he did not want to let the bargain go and thus bought over 10,000 secondhand S9 at the price of 950 yuan ($140), at that time, he expected the payback period to be 10-11 months. Now that the price of bitcoin has increased by two-thirds, the payback days is apparently shortened, maybe below 200 days. As a result, he is looking for more models these days but has to cost double.

According to Zhang, not only local miners are increasing their stock, miners overseas are also eyeing on these old models, especially Whatsminer M3 and Antminer T9+.

“An obsolete M3 (which cost only 200 yuan in the past months) has been priced at 450 yuan, and a secondhand T9+ surged to 700 yuan.” “They are mostly miners from emerging mining countries such as Iran. The mining industry there is in the ascendant and huge amount of mining machines are needed. While it is unlikely for them to buy expensive new high-performance machines considering the damages in the way and maintenance problems, so they prefer those old machines at low cost.”

As Zhang estimates, there might have been 100,000 mining equipment sold to overseas miners. “We’re almost out of stock at home.”

However, the mining rig retailer reminds miners not to “buy high” at this moment, considering the recent bitcoin price jump and hashrate may surge once the anticipated cheap hydro-power is supplied during the water-abundant summer in Sichuan China.