The big issue I have with buying custom plans is:

What kind of instructions come with the plans? Perhaps none at all. Some designers assume you are an experienced builder and just need offsets, specs and drawings. Most of us need advice and assistance, too. If there is now detailed instructions with the plans then you'll have to gather a few books on building similar designs and keep them for reference.

If this is your first boat you would probably be happiest with the "cookie-cutter" plans. Most of these are well proven designs which have lots of previous builders. That means there is a large pool of knowledge about these boats which can be tapped.

A completely original design, while theoretically fitting you better, by definition, does not have any previous builders. That might cause problems if you are not already an experienced builder.

Of course, if the plans are modifications of an existing design then the problem is alleviated. But then, you could probably do the modifications yourself and save the money, or as Nick suggested, have the designer make the changes for you.

Finally, this sounds like a fine service at a reasonable price, but as always buying such things is a trade off between minutes and money. If you wanted to spend the time, rather than the money (and there are few people out there who have an easier time finding stray minutes than stray dollars) then there are several boat design programs available as shareware or freeware and downloadable from the internet.

PGJ