Michael Ash wrote:

That is an interesting way to pay, although it seems unfortunate that I'd
have to pay extra for a go around if one should occur.

That's life. There is no such thing as a pricing system which is fair
for everybody in all circumstances.

My club, like most (I think), charges by altitude and nothing more,

Most clubs I know charge by time. I guess this is regional culture.

Anyway, enough commentary, I have an actual question: roughly what do your
costs work out to for, say, 1500, 2000, and 3000ft tows? Obviously it'll
depend a lot on conditions but I imagine you have some idea of what your
tow will cost before you launch even if it's not exact.

Well, we try very hard not to think about it... :-/

Seriously, it's hard to tell. There is no such thing as a tow to 1500,
2000 and 3000ft at our site (except for student training). There are
tows to certain known or estimated thermals.

The cheapest tow is to a hill right besides the airfield. On reasonable
days you'll find a thermal there on one side or the other. This tow will
be to approximately 2000ft. (You decide when to release: If you feel the
thermals are strong and reliable and forming low, release earlier, if
you think that you have to try and and search and work weak 100 fpm
thermals which form only at altitude, release later.) A "normal" tow
there is about $35 to $40. Caveat: Those thermals form somewhat late in
the day and you will lose a lot of time if you want to go cross country.

If you want to launch earlier and/or plan to do a big flight, you are
better off towing to some known thermically active regions farther away.
This will cost you about twice as much, but not because of altitude, but
because of distance. You see, the "altitude price system" just wouldn't
work here.