Development Set 3.5 vs. 3.51

[Roger Taranto]

When I upgraded my machine from OS 3.5 to 3.51, the installation
instructions said not to use the 3.5 Development set.  Since I wasn't
interested in paying any more money, I kept the 3.5 Development Set.

So, my questions are: what, if anything, will go wrong if I continue
to use the 3.5 Development Set with the 3.51 OS?  Second, how much
is the upgrade to the 3.51 DS, and how difficult is it to get.

-Roger
{mtxinu,ptsfa,amdahl,sun}!rtech!rog