A good place to check out many soundtracks before you buy them at GOG, is Bandcamp.

Soundcloud might be another, etc.

Please feel free to recommend some other good sites to listen at, but youTube is a given, and not really the best way.

Here's some examples.

A Bird Story (OST)
NOTE - You can also download for free, three extra tracks (37, 38 & 39)

Orwell (Original Game Soundtrack)

FEIST Game Original Soundtrack
NOTE - A 13th track is listed, which might not be in the GOG version, and sounds quite good.

FAR: Lone Sails Soundtrack

Enjoy!

And if you do buy from Bandcamp, https://github.com/easlice/bandcamp-downloader/ is an equivalent of gogrepoc for automatically downloading all purchases in desired formats. Not quite as user friendly, but a heck of a lot better than manually downloading them if you buy lots of albums.

[Other downloaders may or may not exist, this is just one that I found, tried and worked well for me]

bandcamp, to my knowledge, gives a far greater share of the price to the artist than e.g. Apple or Amazon.

I usually go for the bandcamp version even if I can get these soundtracks cheaper elsewhere.

If buying from Bandcamp, keep a lookout for Bandcamp Friday (now a rarer event I think) where all proceeds go to the artist / band etc.

Which will happen this friday March 7.
And in the following dates:

May 2nd
August 1st
September 5th
October 3rd
December 5th

According to https://daily.bandcamp.com/features/bandcamp-fridays

O___o
o___O

NICE!