I'm not the best resource for that, but can't resist chiming in
I bought an assortment pack yesterday -- it was $16, I think? Will handle a variety of materials, and then I got the pruning blade today. Per Mr HomeDepot, reciprocating saw blades are universal. So you're not limited to having to get the manufacturer brand.
As one who's had a variety of cordless tools over the years, go for the biggest battery you can afford (I got the DeWalt 20v lithium-ion saw. Mine came with battery, charger, and carrying case, for about $100 more than just the saw alone).
This is mine:
http://www.homedepot.com/p/DEW...
Here's what the pruning blade looks like
http://www.homedepot.com/p/Dia...
edited to add: Asa beat me to it
