we're a startup and we've sent multiple people to offsite training. in general it only costs a couple thousand bucks per class per employee including room and board.

Interesting. Were they otherwise experienced developers who you just needed to train in your particular toolchain, or have you hired inexperienced developers and trained them to be more experienced?

There's training expenses regardless of who you hire. There's training in the work flow and the software stack you use (which you haven't mentioned at all on any of the job posts you mentioned elsewhere). It's never "slot right in and be 100% productive from minute one."

both, although the second type you mention just happens on the job, there isn't really a "get better at everything" class, that's just called work experience.

training classes for specific software is either free (depending on the type of business relationship between the two companies) or $500-$5k with a big cluster around $1500. anything outside of that range is really rare. hotel/flight/car is usually about $1k+ combined in the US. classe usually last a day or two.