What's the most cost effective way of getting 200,000 Skywards miles?

Hi all, I’m trying to figure out what the most cost effective way of getting 200k skywards miles. Without signing up for a credit card… I was looking at buying SPG miles but I see there is an annual limit. I have $2k to spend if I could do it for less that would be great. Any info appreciated

I probably should have explained my situation in a little more detail. I have 200k Qantas points. I usually fly Emirates  from Perth or Sydney to Dublin via Dubai. I would like to have the option to upgrade with points but I cannot use the Qantas points for this. So I was thinking about selling the Qantas points to a mate and buying Emirates Skywards miles instead of them if possible. Hence why I am looking for suggestions.