This is my first time posting here, after a long look on the web it seems by far the best place for this enquiry.
There are two versions of Zapf's "Renaissance Antiqua" available: one from the company which produced it originally, Scangraphic; and the other from Elsner & Flake. Both are available in Opentype but the former is about half the price. Basic descriptions for the text (as opposed to display) version from MyFonts are given below.
Foundry/Vendor Elsner+Flake
Format OpenType
Name ZapfRenaissaBEFOP-Book
Version OTF 2.001;PS 002.000;Core 1.0.29
Family ZapfRenaissaBEFOP-Book
Sub Family Regular
PS Name ZapfRenaissaBEFOP-Book
Filename ZapfRenaissaBEFOP-Book.otf
File Size 29800
Copyright (c) 2003 Veronika Elsner, Guenther Flake GbR; Hamburg. All Rights Reserved.
Glyph Count 246
Character Set Standard
Foundry/Vendor Scangraphic Digital Type Collection
Format OpenType
Name ZapfRenaisSBOP-Book
Version 1.000;PS 001.000;hotconv 1.0.38
Family ZapfRenaisSBOP-Book
Sub Family Regular
PS Name ZapfRenaisSBOP-Book
Filename ZapfRenaisSBOP-Book.otf
File Size 31596
Copyright (c) Scangraphic Prepress Technology GmbH, 1987 - 2003. Veronika Elsner, Guenther Flake GbR, Hamburg 2004
Glyph Count 230
Character Set Standard
The only discussion I can find here about this type concerned the difference between the H (headline) version and the B (bodytext) version, which was settled quickly enough.
The full character map provided at MyFonts is the same in both cases although there is a difference in the glyph count.
If anyone is familiar with using these versions I would be grateful for their advice, particularly as to whether there is any compelling reason not to opt for the cheaper one! I should perhaps say that I am a small-craftsman and not at all informed about the computing technology side of things.