It depends how much you plan on flying next year

But I probably wouldn't do it unless you plan to fly a lot next year. You can get the majority of Silver benefits through the credit card (boarding group 2, free checked bag, etc.). It's not like you're going to get upgrades as a Silver, and E+ often only has middle seats left at T-24, except for some international routes.

You should be able to do 228 miles for much cheaper than $300 RT though. Check Hartford, Dallas, Chicago, etc.