Muller's 4-Vol PRRD for dirt cheap!

[Philip A]

Monergism has Muller's Post Reformation Reformed Dogmatics on sale for $79.

 

[RamistThomist]

I have pretty good luck--er, providence--finding them for $15 a piece on Amazon.

 

[Ivan]

I have pretty good luck--er, providence--finding them for $15 a piece on Amazon.

There are some great deals on used (and sometimes new) books on Amazon and eBay.