Figure 20% down on the boat and $6,000 to $10,000 as a cushion that may be needed to sink in fast (or to keep from sinking fast) bayond all your other short-term living expenses. Plus you have to insure/slip/register up front and that's $2,500 to $3,000 depending on how many months out the slip is for (6 mo or 12 mo).
I forsee banks/lenders dropping the "no money down" philosophy and insisting on the 20% chunk up front.
You should be able to find a Catalina 30 for $35,000 or a Han Christian 33 from about 1890 for the same price. Seriously, I don't think the oldest Hans Christians have yet fallen to what a NEW C30 goes for.
Freedom 30 may be a good choice. I know of a very nice F32 that may be on the market come spring on the Eastern Shore.
Charlie P. Mud Hen 17 #69 Mad Hatter
To travel hopefully is a better thing than to arrive - R.L. Stevenson
I suspect that, if you should go to the end of the world, you would find somebody there going farther . . . - H.D. Thoreau