As Uberdude said, it depends on which pincer. If you suggest a pincer, one of us could probably give you an example continuation. If White has already made the low approach at 5-3 in the bottom left, extending with the marked stone is a normal continuation. This is because White can press Black's lower left corner and trade territory for influence at any time, so the extension is stronger than it looks. However, White doesn't want to just press straight away before extending, because White has many other options depending on how the game develops (e.g. counter-pincer, slide, attachment, etc). And generally it's not a good idea to trade cash for an uncertain investment in the future until you have sufficient information and a clear plan.
From memory, I think this kind of extension is discussed in Opening Theory Made Easy.
Also, I thought you were Black when I first commented, so I thought I was showing you a better move, but now I realize that you were White. Sorry if you didn't find this helpful.
Pippen wrote:Also: If white plays a and Black plays 1 then the sequence you showed then White could simply tenuki at some early point, treating the stones there lightly, couldn't he? That'd be my approach.
Pippen wrote:Here are two further questions, also refering to fuseki:
1) In this diagramm should black play the joseki 6-10 or pincer at a, b or c after 8 (or maybe pincer right at 6?)? I think c after 8 is not good because it harms 5 indirect, but a/b or an immediate pincer after 6? Or is it just a matter of taste?
in the top right corner invites , which works with the stone.
2) The fuseki continues with 11, but is 17 a good move and even more: where to play after 18 for black (I usually play at a)? Do you like black's position?
FWIW, my take is that black is possibly very slighty better at move 22 (e.g. by around 0.1 of a move).
I'd happily play with white, since middle game noise tends to swamp differences that small.
My reason for preferring black is the stone at K3. This feels overconcentrated - if white had fisrt got the shape in the lower left, next extending at k3 is an eccentric move. It's too close to the thickness.
However, it's a small error. The reply in the top left, starting at move 24, feels like a bigger error to me. White gets a heavy group whilst black takes the corner and gets a wall on the side. I'm not quite sure what the mistake was, but:
Atari at move 34 feels crude and removes a cut a H17. 26 at G17 is ceratinly justifable. You get territory and black's wall is a bit pointless. Alternatively, since you are thick, 26 as a cut may work. The 34-36 combination feels very heavy to me. Could you go into the 3-3 point with 34 and play more lightly here?
By the time move 37 appears, I reckon you're about 1 stone behind. So the middle game error was far more material than the opening one...
Here's a new example, white to play, but where? My feeling was that b was more urgent and important than a, but of course with "a" white simplifies and gets sente while with "b" black will fly to the right side, damaging the white split stone and white will probably end in gote. So, where would u prefer to play and is it still an even fuseki? Also interesting: Suppose white plays b and black plays the normal attachment underneath. Do you push him down to make the split stone work or do you still prefer the joseki where white gets the side?
Pippen wrote:Here's a new example, white to play, but where? My feeling was that b was more urgent and important than a, but of course with "a" white simplifies and gets sente while with "b" black will fly to the right side, damaging the white split stone and white will probably end in gote. So, where would u prefer to play and is it still an even fuseki? Also interesting: Suppose white plays b and black plays the normal attachment underneath. Do you push him down to make the split stone work or do you still prefer the joseki where white gets the side?
I'd like the marked stone to be one space to the left of where it is, to be honest. Apart from that, I'm also quite tempted to take something near Q10, since the marked stone makes a corner enclosure smaller for black, and the right side is very big for both players. What order were these moves played in?
I don't think it's terribly unbalanced, but my feeling is that it favours black a bit, because all his stones are coordinated while the marked stone feels odd. If white A, black Q10 or something around there in gote, then white B, black can handle the pressure on his corner stone. If black responds with B instead, and white takes Q10, white provoked black to make his corner enclosure, and black can probably look forward to decent gains by attacking. If white B, black E15 may work well to split.
Not to endorse White's earlier play, but I think that White has an edge.
has no base, but is not severely pressed. is healthy (unless I have misread the 3-3 attachment). And it looks as though White is going to get a moyo, one way or another. Meanwhile, Black's position is hardly dynamic.
The Adkins Principle: At some point, doesn't thinking have to go on?
— Winona Adkins
I think 1 is not a mistake, but the best move for black? Anyways, White continues with 2...should black just fly to a? Or should black invade the white moyo and most importantly - if you were to invade/reduce it now (instead of a) where would u start here?
My first thought would be to attach at , to expand the B right side while limiting the W upper side. This aims to maximize the effectiveness of the marked B stone and minimize the efficiency of the marked W stone.
Invading the W position instead seems like the wrong direction. In the resulting running fight, the marked W stone is guaranteed to become very useful, while the influence of the marked B stone could easily be damaged.
(or 'a') seems better; as skydyr said.
and 
are questionable and Black becomes thick
.
, which works with the 
stone.
, but after 
I like something like 
below, on the frontier of moyos.
A play at "c" threatens "d".
has no base, but is not severely pressed. 
, to expand the B right side while limiting the W upper side. This aims to maximize the effectiveness of the marked B stone and minimize the efficiency of the marked W stone.