Why does 4.dxc5 work well for white in the Advance variation of Caro-Kann? [FEN ""]
1.e4 c6 2.d4 d5 3.e5 c5 4. dxc5


I don't want to play 3...bf5 instead, but this 4.dxc5 line in the Advance Variation gives me so much trouble, whether they go with 5.Be3, 5.a3 or 5.Nf3.


What's a good way for black to deal with this 4.dxc5 line?
First, I would wonder why you do not want to play 3...Bf5 first? That is the most common move, and the most natural.

3...c5 almost forces you to gambit a pawn, and if you are not comfortable playing very tactical positions down a pawn, you will want to avoid the immediate c5 in the future (it is still the move you will want to play eventually to free your game, but you will want to prepare it so you are not just losing a pawn for play).

After 3...c5 4 dxc5, here is the main line. (There are a fair amount of written prose notes in the comments below, so make sure you read those too.)

 [FEN ""]

 1. e4 c6 2. d4 d5 3. e5 c5 4. dxc5 Nc6 5. Bb5 (5. Nf3 Bg4 6. c3 e6 (6... Bxf3 7. Qxf3 Nxe5 8. Bb5+ Nc6 9. O-O $16) (6... Nxe5 $4 7. Nxe5 $1 Bxd1 8. Bb5+ Qd7 9. Bxd7+ $18) 7. Be3 Nge7 8. Nbd2 Nf5 9. Bd4 $14 Nfxd4 $2 10. cxd4 Nxd4 $4 11. Qa4+ $18) 5...e6 6. Be3 Nge7 7. c3 Bd7 8. Bxc6 Nxc6 9. f4 {And there are several moves here, most requiring black to be a pawn down. In exchange for that, black has the bishop pair, the white king has been weakened with f4, and black is slightly ahead in development, so you have to play very actively.  Here, I would recommend either b6, or the main book move, g5. a5 is also possible trying to round up c5 at some point.} g5 (9... b6 10. cxb6 axb6 {And now, you also have an open rook file, and can aim for b5-b4 after getting the Bf8 out. you may also play the Bf8 to c5 with the idea that if white trades, you will have strong pressure for the pawn down the a-file and b-file...a bit like the Benko, but reversed.}) 10. fxg5 Nxe5 (10... h6 $5 {Has been played.}) 11. Nf3 {With a wild game with chances for both sides.}