With the release of volume 4 I was having a bit of a search and found that the original volumes were selling for a wee bit more than I might have guessed. The plan now is to hold on to them for a few more years, cash in and retire

https://www.abebooks.com/book-search/title/black-cross-red-star-volume-1/

What the link shows is a used copy of Black Cross Red Star selling for US$521. Well, "selling" might be assuming too much. But that's the listed price. With everyone having bought these books when Il-2 came out I suspected some might find this interesting....

Yep, got all of the first three volumes, but not got the new one yet...

If you plan to sell yours do it quick, reedition is reportedly planned.

Well dammit that will scupper my retirement plan.

There is a 5th volume planned for publication later this year. For those interested, info can be found here:

Volume 5