Charts and pilot books are a knotty subject. The practice of borrowing charts from other boats, and photocopying them, is very widespread. Most significant ports have shops where charts can be photocopied full size. We bought a number of charts before leaving England, many second-hand from a supplier who makes all the necessary corrections, then sells the charts on at about half price. We also bought all the pilot books we thought we'd need.
Photocopying charts is illegal, or at least a breach of copyright. It is an extremely tempting proposition, though, when the boat next door has a chart you need, and it can't be bought for love or money anywhere near where you are.
Last time we were out in the Caribbean Don Street, who has some connection with the Imray-Iolaire charts (and probably gets a rake-off on each one sold), had put up notices in all the marinas threatening with dire penalties anyone who photocopied said charts, or aided and abetted the procedure. He has a valid point, of course, but the approach seemed at best futile and at worst counterproductive - more likely to annoy yachties than persuade them to buy his charts.
If nothing else, if you're coming to the Caribbean I'd recommend you buy Chris Doyle's Cruising guides These are written in an entertaining manner and contain lots of useful information, not just about sailing and pilotage, but also about eating and drinking ashore, local services, transport, sightseeing and all the rest. They're fun to read and value for money, and are regularly updated. This doesn't mean they're always right up to date (they're not) or that I agree with all his opinions (I don't). But, all in all, they're about the best Cruising guides to ANYWHERE that I've read, for what that's worth.