How much is the I-290 W Exit 7 toll in M?

I don't know the rate scale anymore (EZ P), but would suggest you avoid the congestion on Worchester by using I-495 to I-90 west. I-90 to x7, I-84 then south. Toll should be around $5 for that longer stretch, but the driving easier. If you are going down to I-95, don't forget 15 at Hartford to I-91 south.