No-Brainer buy?

Hi everyone, just thinking that with retiring sets normally always increasing after they finally finished: is it a no-brainer to buy sets that are about to retire and available at a discount?

I’m able to buy 40 LEGO Tales of the Space Age (set # 21340) for about 30% less than the normal price and I’m happy to sit on them for a year. Thanks for any help

This would be my first time buying lego as an investment as I typically only buy the occasional Star Wars set for fun.