Yes, there are multiple flights from Bangkok to Algeria for under ฿ 47,994. The cheapest flight booked recently is on Qatar Airways for just ฿ 45,205, but on average you can expect to pay ฿ 51,324.
There are no direct flights from Bangkok to Algeria, but Cheapflights can provide you with all the information you need to find the fastest route with the fewest stops.
Qatar Airways and KLM can get you from Bangkok to Algeria in just under 17h 50m. Your travel time can differ by up to 10h 40m. Both multi-stop and direct flights can be found to your destination and back.
Flying on Qatar Airways is currently your cheapest option to Algeria, with prices starting at ฿ 45,205. Another option worth looking into is KLM, starting at ฿ 56,754 return.