There are lots of tour companies which organise city tours in Wrocław, but the one you mention seems very expensive. Google for others and compare prices.
350 PLN for a city walking tour is way over the top.
There are free walking tours of the city available in Wrocław, although obviously it would be nice to leave a tip for whoever is guiding you around.
Here is the link:
Hi cindy5, a good suggestion from chemikiem. The tours usually start by meeting at the Alexander Fredo statue in the main market square, between November and March they start at 10.00 everyday for a tour of the old town, about 2.5 hours. There is also a daily tour starting at 13.30 that tours the Jewish quarter, just arrive a little earlier and look for the ''free walking tour'' stick, if for any reason they can't meet at the statue they meet about 50 mtrs away between Main square and Solney square, if you are with a group of friends (7 or more) you do need to phone them up. Have a great time in Wroclaw it's a beautiful city.
All they ask for is a donation.