Boost Mobile offer of Xfinity Internet?

I got an email from Boost offering a PREPAID INTERNET deal from Xfinity for $45 a month. I'm already an X customer for my net, though not prepaid, for about $105 a month. 

But the fine print in the offer says "Limited to download speeds up to 50 Mbps and upload speeds up to 10 Mbps". That seems only a quarter or less of my current Performance plan of 200/100. I don't want to downgrade my ACTUAL service, in contrast to the promised speeds.

Opinions?