My wife and I both have XM units I installed in our cars (before the Sirius/XM merger). If you don't want bells and whistles (ability to record shows, internal antennas to pull unit out of car and use...fancy color displays), you can probably get a unit for around $50-75 (just a guess though).

Even though sirius and XM are the same company now... they don't offer the same programming. If you want to listen to baseball games... I am almost certain you have to subscribe through XM (no additional charge). From what I understand, if you are a Sirius subscriber, and get the "Best of XM" package (some sports programming and Opie and Anthony)... I do not think the baseball games are available (there's some kind of battle between Sirius/XM and MLB about the contract, this was a month ago I heard this... not sure if it is still true). It's not true the other way around with respect to football (if you are an XM subscriber, and pay extra to get the "Best of Sirius" (football and Howard Stern's channels), then you can listen to NFL games).

When I first got it, it was around $13 a month, an extra $7 a month for a second unit (we actually got a free reciever when signing up the extra account). If you pay for a year, the discount was that you got one free month... I think now we do a 3-yr subscription as it's significantly cheaper.

Unless they go out of business... I'll never listen to terrestrial radio again.