Where is the best bang for your buck to get a new crate motor?
it helps if you tell us what size motor you are wanting? a 2.5 liter, 3 liter, 4.1 liter, 4.3 liter, 5.0 liter, 5.7 liter, 6.0 liter, 6.2 liter, 6.6 liter, 7.4 liter, 8.1 liter, or 8.2 liter (I think I covered all the common boat offering sizes from GM)
the 2.5, 4.1, 4.3, 7.4, and 7.5 have ceased normal production. the 8.2 is performance catalog only, the 6.2 liter is available in both a Gen 1 and Gen 3 configuration. the 6.0, 6.2, and 6.6 are gen 3s, the 4.3 is being phased out, the 5.0 and 5.7 are soon there after (although heavily supported by the aftermarket)
you kind of get the point.
best bang for the buck is dependant on your situation, your budget and what you want. it may be taking your existing block and heads to your local machine shop, it may be buying a reman, or it may be buying a new crate motor.