Wife bought First Class for two SAN-SEA and one SAN-SFO for trips this fall that she'd otherwise fly coach. Kind of a waste because she had excellent upgrade chances on my Diamond coattails. This was to get her from Plat to Diamond because she was short a bit more MQD's than OP.
Zorak's answer is comprehensive on the facts. The benefits of Medallion status get better the farther one climbs the Silver, Gold, Plat, Diamond ladder. Silver in Skymiles is not worth $1300 in extra spend in my opinion. (OP does not explicitly say which status jump he's considering. If it is "first time", then probably it's Member to Silver.) However, everyone's situation is different. It is possible OP has a boatload of MQM's that won't rollover into 2022 without reaching (any) Medallion status.