Are you looking for the floss version or the printed version?
I found the printed version pretty cheap on Amazon.fr but the floss versions all look to be around 35-40€
DMC Colorcrd Fils à coudre 12 pages imprimées sur carte couleur https://www.amazon.fr/dp/B001C1NMO2/ref=cm_sw_r_awdo_ERYAJ28N4RC8Y925WKCV
Joann's and Micheal's always have a fairly small selection of DMC. I hate to say this since Hobby Lobby is a truly awful business, but they have one entire eisle devoted to DMC thread and usually have a pretty okay selection (it's usually only a couple skeins of each thread and you'll have to be careful because the colors are usually all mixed up)
Because Hobby Lobby can go jump in the sea, I'd recommend finding a local needlepoint shop that partners with DMC or Anchor thread (a similar brand). If there's nothing local around, you could also purchase the DMC Color Card and purchase off the DMC site itself. The card isn't going to be 100% accurate, but it's pretty close!
I tried looking in my PCStitch program, but Trebla is not listed for conversion. I would suggest buying a DMC color card and bringing that to match colors in the store.
I found this one on Amazon. Would this do the trick?
DMC COLORCRD Needlework Threads 12-Page Printed Color Card https://www.amazon.com/dp/B001C1NMO2/ref=cm_sw_r_cp_api_glt_i_G1718WJ10N82XDW5CDPX
I bought a DMC color card to match threads. They’re sold on Amazon. DMC COLORCRD Needlework Threads 12-Page Printed Color Card https://www.amazon.com/dp/B001C1NMO2/ref=cm_sw_r_cp_api_i_frQKDbND4XCF3
The one with actual thread is not made anymore. The one with pictures is available on Amazon (DMC COLORCRD Needlework Threads 12-Page Printed Color Card https://www.amazon.ca/dp/B001C1NMO2/ref=cm_sw_r_sms_apa_i_dEvrFb1RGPY01)